Both are grammatically correct sentences, but they mean (slightly) different things.

"Rice grows in the south of China"

This means that rice <em>is able</em> to grow in the south of China. For example you could also say "Strawberries grow in the summer." There is a passive feeling to this sentence, there is no "doer" (i.e. no person in the sentence who is doing the growing)

"Rice is grown in the south of China"

This means that rice is grown (by someone) in the south of China. This sentence is basically the same as "Rice is grown by farmers in the south of China."

So the difference is, the first sentence is about the ability of rice to grow, and the second sentence is about rice being grown (by some farmers). I hope that helps!

Attending a wedding

I went to attend a wedding today (you can either say "I attended a wedding today" or "I went to a wedding today") with my mom. The bride and bridegroom's ("bridegroom" is correct, but it is rarely used) parents sent two buses to pick us and other guests up at 11 o'clock, then sent us to the wedding hotel where the wedding was (or "where the wedding was being held"). The wedding started at 12 o'clock, and we had already sat down at that time. It's was really beautiful and romantic there. First, the bride’s father led his daughter walked out; (or, "walked his daughter down the aisle." This is what we would normally say.) she was a very beautiful bride., and The bridegroom walked in front of them, then, while the bride's father was hand his daughter to the bridegroom,. It was a moving scene. After the couple exchanged the ring and finished some the ceremony, we can started to have dinner.

Looks good! Remember to keep your tense consistent. If you're talking about something that happened in the past (like this wedding), make sure to always use past tense. I made a lot of corrections, but I had no problem understanding what you wrote.

Your letter is good, I don't see anything "wrong" with it, but I will make some changse to make it sound more fluent. Corrections in red, comments in blue.

Dear Mr. Smith,

I am the human resource manager of CMCC. Our company is the single largest mobile network operator in China and a leading telephone network operator and internet service provider in the world (see note 1 below). We provide our customers with first-class communication means and various information sources.

Currently, in order to boost our company’s morale (see note 2), we plan to hold a big meeting next month. We need a guest speaker to give our staff a speech in the meeting on ‘Collaboration and Trust Building’. Considering your background, we would like to ask if you are interested (see note 3). If you can take the job, please let us know the times you will be available.

A meeting room that is big enough for 100 people and equipped with a projector for giving presentations will be available at that time. Additionally, a dedicated internet connection will be used to transfer broadcast the speech to all our branches for all employees to watch.

We will be grateful if you can give us a reply at your earliest convenience so that we can supply more details to you and make appropriate preparations in time. Thank you.

Yours sincerely,
Nelson Lee

1. "...largest mobile network operator in China and a leading telephone network operator and internet service provider in the world." This should be changed. If you say "...the leading network operator..." this means you are the largest in China. If you say "...a leading network operator and internet service provider." this means you are <em>one of</em> the biggest (but maybe not <em>the</em> biggest). What you currently have is a mixture of the two, so change it to whichever one you mean.

2. "Currently, in order to boost our company’s morale..." First, saying "in order to boost our company's morale" makes it sound like the company's morale is very low (perhaps because something bad happened, like a death or a natural disaster). I would suggest changing it to "In order to help motivate our employees..." or "In order to boost employee productivity...". You can also simply remove that part and start with "We plan to hold a big meeting next month, and would like..."

3. "Considering your background, we would like to ask if you are interested." The problem with this sentence is that "...ask if you are interested" does not directly relate to "considering your background..." Instead I would write, "Considering your background, we feel you would be an excellent (or exceptional, perfect, etc.) choice. If you are interested in taking the job..."

Looks great!

Truth vs Lies

I always have said I appreciate the “truth,” which can help me growing more quickly. But I don't think I can handle it very well.
One day, my sister told me that the skin of my face looked really “terrible,” and had so much many speckles on it, which devastated me badly, me because smooth and good skin has always been my unbeatable advantage best attribute. (saying "unbeatable advantage" makes it sound like you're competing with other people. "best attribute" just means it's the best thing about your appearance.)

I didn't want to hear this at all. Then I understand understood the reason why people love to hear beautiful lies,; it actually makes you really happy and confident. I accepted this truth after this thought hanging in my head a the whole day,. So then I decided not to stay up late and eat healthy.
It's better your relatives say it out loud, than having others laugh at you in their hearts. At In the end, I still value the “truth.”

Introduceing my hometown

I was born in Beijing, It's the capital of China. The city is very large and has very many people (or "has a lot of people"). It's a very beautiful and modern city, and of course there are many places of historical interest in history, like The Great Wall, Summer Palace, Temple of heaven, The Imperial Palace and so on (or "and so forth").