There is an official business trip next week and I will be leading the team. There is an official business trip next week and I will be leading the team.

What you wrote is correct, but this way sounds more natural.

There is an official business trip next week and I will be leading the team. There is an official business trip next week and I will be leading the team.

There is an official business trip at my work next week and I will be leading the team. There is an official business trip at my work next week and I will be leading the team.

AOne of my colleagues thinks that I don't have a decent suit and suggested that I buy a new one. One of my colleagues thinks that I don't have a decent suit and suggested that I buy a new one.

"A colleague" could be anyone, but "one of my colleagues" makes it clear that it's one of the colleagues who is going on the trip.

A colleague thinks that I don't have a decent suit, and they've suggested that I buy a new one. A colleague thinks that I don't have a decent suit, and they've suggested that I buy a new one.

I went to the Hailanzhijia under my office building office and bought a pair of leather shoes, a trousers and a shirt. I went to the Hailanzhijia under my office building and bought a pair of leather shoes, trousers and a shirt.

You could also say "a paur of trousers."

I went to the Hailanzhijia under my office building office and bought a pair of leather shoes, a trousers, and a shirt. I went to the Hailanzhijia under my office building and bought a pair of leather shoes, trousers, and a shirt.

I went to the Hailanzhijia under my, which is located downstairs from my office building office and bought a pair of leather shoes, a pair of trousers and a shirt. I went to the Hailanzhijia, which is located downstairs from my office building and bought a pair of leather shoes, a pair of trousers and a shirt.

The leather shoes cost more than 400 CNYyuan, the trousers and the shirts each cost more than 300 CNYyuan. The leather shoes cost more than 400 yuan, the trousers and the shirts each cost more than 300 yuan.

CNY is a more official abbreviation for formal contexts (like if you were writing a business report or listing statistics). "Yuan" is used in everyday speech.

The leather shoes cost more than 400 CNY, and the trousers and the shirts each cost more than 300 CNY each. The leather shoes cost more than 400 CNY, and the trousers and shirt cost more than 300 CNY each.

I was a little confused because you had "shirts" singular up top, so I decided to go with that. Besides that the sentences was correct, but I changed it to sound more natural and add emphasis.

I think they are very expensive and I have never bought such expensive clothesing. I think they are very expensive and I have never bought such expensive clothing.

"They are" can also be "They're". "I have" can also be "I've".

I think they are very expensive ands I have never bought such expensive clothes before. I think they are very expensive as I have never bought such expensive clothes before.

WhatI was surprised me isto find that the shirt is attached tohas a layer of velvet inside. I was surprised to find that the shirt has a layer of velvet inside.

Again, what you wrote is correct, but this version is more idiomatic/natural.

WhatI was surprised me isby the fact that the shirt is attached to a layer of velvet on the inside. I was surprised by the fact that the shirt is attached to a layer of velvet on the inside.

What surprised me is that the shirt is attached tolined with a layer of velvet inside. What surprised me is that the shirt is lined with a layer of velvet inside.

This is the first time I know that there is've ever seen this kind of shirt. This is the first time I've ever seen this kind of shirt.

This is the first time I know that there is've encountered this kind of shirt. This is the first time I've encountered this kind of shirt.

This is the first time I know that there ishave seen this kind of shirt. This is the first time I have seen this kind of shirt.

It i's vpery suitable to wear infect for the season between autumn and winter. It's perfect for the season between autumn and winter.

"Suitable" is a little too formal and it sounds rather unnatural.

It is very suitable to wear infor the season between autumn and winter. It is suitable for the season between autumn and winter.

"It is" can also be "It's".

It is very suitable to wear in the season between autumn and winter. It is very suitable to wear in between autumn and winter.

I think I look bettergood in this suit. I think I look good in this suit.

If you say, "I look better," it means that you're comparing that to something else. So you could say, "I look better in this suit than I did in my old one." You could also say, "I look better in this suit than I thought I would."

I think that I look better in this suit. I think that I look better in this suit.

I wasn't sure if you meant for this to be a statement or not.

I look bettergood in this suit. I look good in this suit.

It sounds odd to use "better", as it is a comparative word. Since you have not established wearing any other type of clothes, it is sufficient to just say you look good in this suit.