This is the way I would do it (only partial...so long)...some is just style and some is a real puctuation or grammar error corrected.

Writing Practice IV [style]

Here I am!![new paragraph shifts to new idea or thought]

The following passage is another writing practice I've just done. Please help me correct it or improve it.  I'd love to correct my mistakes and[don't repeat yourself...you just said the same statement in your last sentence] learn more.  I would be grateful if anyone would help me.

DIRECTIONS:
Write an essay of 160-200 words based on the following dreawing.In your essay, you should  [are you training using British English or American English?]
1.describe the drewing briefly
2.explain its intended meaning, and then
3. give your comments.

(Here comes my essay)
As we can see from the picture, there is a huge net which has connected everyone all over the world, no matter young and old, men and women. People from every corner of the world are keeping in touch with each other by clicking the mouse and pressing the keyboard. With its convenience, Internet is narrowing the distance among people in both space and time.
However the drawing also tells: those "walls" emerge unnoticed among people when they are enjoying surfing online. As the time people spend on Internet is on the rise, face-to-face communication has reduced. The reduction of contact in real world may result the feelings of distance among people. So many examples can prove this.
Obviously, Internet is totally convenience, helpful and efficiency, but we shouldn't over rely on it to communicate, whereas we need to interact with others in our real world. So we need to learn how to use the Internet to make our lives more beautiful and wonderful, meanwhile we need to respect real people in real life.


Thank you so much for your patience! ^^

Writing Practice 4

I think you are writing a novel!

Here I am! The following passage is another writing practice that I've just done. Please help me correct it or improve it.  I'd love to correct my mistakes and learn more. I would be grateful if anyone would help me.

DIRECTIONS:
Write an essay of 160-200 words based on the following drawing. In your essay, you should
1.describe the drawing briefly
2.explain its intended meaning, and then
3. give your comments.

(Here comes my essay)
As we can see from the picture, there is a huge net which has connected everyone all over in the world.
-> idiomatic usage; everyone from all over the world or everyone in the world

No matter young and old, men and women, people from every corner of the world are keeping in touch with each other by clicking the mouse and pressing the keyboard.

With its convenience, the Internet is narrowing the distance among people in both space and time.
Might be more natural to put 'with its convenience' at the end of the sentence.
The Internet is narrowing the distance among people in both space and time with its convenience.

However the drawing also tells: those "walls" emerge unnoticed among people when they are enjoying surfing online.
However the drawing also shows that unnoticed "walls" can emerge between people while they surfing online.  (I don't know if enjoying surfing online is wrong but it sounds odd to say so I would leave one out or say something like 'while they are having fun surfing online')

As the time people spend on Internet is on the rise, face-to-face communication has reduced.
Face-to-face communication has gone down as people spend more and more time on the Internet.

The reduction of contact in real world may result the feelings of distance among people.
The reduction of contact in the real world may cause feelings of distance among people.

So many examples can prove this.
There are many examples which can prove this.

Obviously, Internet is totally convenience, helpful and efficiency,
Obviously the Internet is totally convenient, helpful and efficient.

but we shouldn't over rely on it to communicate, whereas we need to interact with others in our real world.
But since we need to interact with others in the the real world we should't rely on it to communicate.

So we need to learn how to use the Internet to make our lives more beautiful and wonderful, meanwhile we need to respect real people in real life.
Therefore we must learn how to use the Internet to make our lives more beautiful and wonderful.  At the same time, we need to respect real people in real life.

Thank you so much for your patience! ^^
You're doing great!  Maybe try reordering your sentences occassionally if you feel the opening phrase requires a comma.  Sometimes just putting them in the reverse order allows for a smoother sentence.  I am only guessing this because I am having the exact opposite problem when I try to make sentences in 汉语!