When I was atin middle school, I liked geography the moswas my favorite subject.

Sounds better

We learnt somethings like how many big mountains, rivers, deserts and so on there were in China.

If you start a sentence by "how many", it has to contain a verb.

Our geography teacher, Mr. Chen loved to draw a big China map on the blackboard ad then toldell us aboveut things.

above = on, a position higher than a definite reference frame
about = indicates the topic of something
I don't know Chinese politeness rules concerning names, but in English, it's better not to use a family name like this without honorific mention like "Mr."

The reason why I liked geography the moswas my favorite suject was because it was visible and touchable.

Because I had a good grades in geography, teacher Chen always let me, along with a few other students, revised our classmate's' geography test paper with a few other students after every test.

"A" can only be used in the singular, here you have a plural; here "revise" is an infinitive, your conjugated verb is "let"
The Saxon genitive in the plural form is just the pluralized word + an apostrophe, unless the plural word doesn't end with an "s", ex "children's"

I thought this shouldhad to be the most glorious thing I had to do in middle school.

If you want to express something uncertain, a probability in the past, you should use "had to"

But things didweren't always go wthat good, I fellt like this, in my impression, I had got a score justI scored slightly overing forty in a mathematics quiz and I still don't even know what's going on until nowhow it happened.

History was the subject I hated the most because I thought it was very boring and I had to remember a lots of contents about it.

"content" in the generic, abstract sense is like "data", it's uncountable and can't be pluralized. You can pluralize it if the things included in it are countable, for instance, a book page listing chapters may be called "contents", but to a learner, I wouldn't recommend pluralizing it at all

Physicals was the subject we loved the most; we regarded it just as a playing activitymy classmates' favorite subject; we considered it to be a mere game.

I'd specify "my classmates'" since that "we" may be a little obscure here

It meanst we doidn't have to take out a textbook and, just dto somejust playing games a little; If you doidn't want to do it, you canould just relax you self at willas much as you wanted.

The whole sentence should be in the preterit tense here

The other subjects awere fine, and I can't say I (particularly) like itd or dislike itd them.

Plural => "them", not "it"

These awere my attitudes toward the all subjects when I was in middle school.

Once again, these attitudes belong to the past, so preterit tense