For me, they are anotherdifferent things in Chinese and English. For me, they are different things in Chinese and English.

- I believe her when she says she uses lotion, in an ice rink environment, the skin dries very quickly. - I believe her when she says she uses lotion in an ice rink environment, the skin dries very quickly.

- I believe her when she says she uses lotion, in ice rink environments, the skin dries very quickly. - I believe her when she says she uses lotion, in ice rinks, the skin dries very quickly.

- I believe her when she says she uses lotion, in ice rink environment, the because/; (her) skin dries very quickly. - I believe her when she says she uses lotion in ice rink environment because/; (her) skin dries very quickly.

An independent sentence (a sentence that makes sense on its own), followed by another independent sentence needs a semi colon. Or else, you have to have a conjunction like "because" or "as."

why there isn't any conjecture behind the comma? why there isn't any conjecture behind the comma?

When you're giving a reason for something in English, it's usually ok to omit "because" so long as it doesn't start the sentence. "This is disgraceful, (because) look at the mess!" "I'm going home, (because) it's getting late" "Your son has been performing poorly, (because) he needs to study more" "I believe her when she says she uses lotion, (because) in ice rinks, the skin dries very quickly."

why there isn't any conjecture behind the comma? why there isn't any conjecture behind the comma?

Conjecture doesn't make sense here because it means an opinion/conclusion. I think you mean conjunction? Anyways like I said, that sentence is wrong. It needs a conjunction OR needs a semi-colon (;) instead of a comma. This is because a comma is not strong enough to link two independent sentences. Alternatively, you can replace the comma with a full stop.

It is sometimes argued that people should dedicate their lives to the colonization of Mars. It is sometimes argued that people should dedicate their lives to the colonization of Mars.

It is sometimes argued that people should dedicate themselves to the colonization of Mars. It is sometimes argued that people should dedicate themselves to the colonization of Mars.

It is sometimes argued that people should dedicate to the colonization of Mars. It is sometimes argued that people should dedicate to the colonization of Mars.

dedicate what? dedicate is a transitive verb and needs an object afterwards - dedicate themselves/resources/their time

Admittedly, thea Mars colony could prevenotect humanity from the risk of planetary extinction. Admittedly, a Mars colony could protect humanity from the risk of planetary extinction.

You could say: "Admittedly, a Mars colony could prevent the risk of planetary extinction."

Admittedly, thea Mars colony could prevent humanity from the risk of planetary extinction. Admittedly, a Mars colony could prevent humanity from the risk of planetary extinction.

there is no specific Mars colony so you have to use "a"

Firstly, colonizing Mars does not help in solvinge any of our existing problems. Firstly, colonizing Mars does not help solve any of our existing problems.

Secondly, there is not any economic reason for us to do so. Secondly, there is no economic reason for us to do so.

Secondly, there is not any economic reason for us to do so. Secondly, there is no economic reason for us to do so.

there is not any --> there is no (noun)

I believe that humans already have a sufficient level of technology for this plan, but the limiting factors always lie in the cost. I believe that humans already have a sufficient level of technology for this plan, but the limiting factors always lie in the cost.

I believe that humans already have a sufficient level of technology for this plan, but the limiting factors always lie in cost. I believe that humans already have a sufficient level of technology for this plan, but the limiting factors always lie in cost.

"humanity" may be a more appropriate word to use when talking about human society in general. " I believe that humanity already has a sufficient level of technology... "

I believe that humans already have a sufficient level of technology for this plan, but the limiting factors always lie in costendeavor, but cost is always a part of the limiting factors. I believe that humans already have a sufficient level of technology for this endeavor, but cost is always a part of the limiting factors.

There is not really a specific plan to colonise Mars right now and it's more of a goal. So I would not use "plan" The way you phrased it before was a bit ambigious as in whether the cost was a part of limiting factors, or if limiting factors was a part of the cost

To be more specific, it does not make sense to invest a bunch of costsso much in order to colonize Mars without any short-term benefit. To be more specific, it does not make sense to invest so much in order to colonize Mars without any short-term benefit.

As an aside, "a bunch" is quite casual language. It may not be very appropriate for this style of writing.

Most of the colonization that happened on eEarth had economic incentives, such as spices or gold, which can reap people rewards in a short period of time. Most of the colonization that happened on Earth had economic incentives, such as spices or gold, which can reap rewards in a short period of time.

Most of the colonization that happened on eEarth had economic incentives, such as spices or gold, which can reap peopleenabled people to reap rewards in a short period of time. Most of the colonization on Earth had economic incentives, such as spices or gold, which enabled people to reap rewards in a short period of time.

You are talking about the past so I changed it to past tense Earth is proper noun reap + (two nouns) sounds weird, so I changed it so people is the subject

In conclusion, I believe that many factors need to be considered, and there are more issues that call for urgent solving on Earth. In conclusion, I believe that many factors need to be considered, and there are more issues that call for urgent solving on Earth.

In conclusion, I believe that many factors need to be considered, and that there are more pressing issues that call for urgent resolvingutions on Earth. In conclusion, I believe that many factors need to be considered, and that there are more pressing issues that call for urgent resolutions on Earth.

In conclusion, I believe that many factors need to be considered, and there are more issues call for urgenturgent issues to be solvinged on Earth. In conclusion, I believe that many factors need to be considered, and there are more urgent issues to be solved on Earth.

That is to say, issues like overpopulation, environmental protection, and starvfaminge need to be urgently addressed, butand there is nothing any Mars colony canould help with, within a short time. That is to say, issues like overpopulation, environmental protection, and famine need to be urgently addressed, and there is nothing any Mars colony could help with, within a short time.

That is to say, issues like overpopulation, environmental protection, and starvingglobal climate change, and world hunger need to be urgently addressed, but there is nothing a Mars colony canould help with in athe short timeerm. That is to say, issues like overpopulation, global climate change, and world hunger need to be urgently addressed, but there is nothing a Mars colony could help with in the short term.

That is to say, issues like overpopulation, environmental protection, and starving need to be urgently addressed, but there is nothing with which a Mars colony can help within a short time. That is to say, issues like overpopulation, environmental protection, and starving need to be urgently addressed, but there is nothing with which a Mars colony can help within a short time.

Or "there is nothing a Mars colony can help with" (technically not grammatically correct but far more common, especially in spoken English)