Hi! The -ing form (gerund) means the action is about to or is happening (most of the time). The infinitive with 'to' usually comes after the gerund. For instance: I am going to eat. Here 'going' shows that he is about to do something while 'to eat' is the infinitive form which is about to happen.

The converted plates serve to drill a passage in the wood, and the course itself is cemented with lime.

Maybe use a different word instead of 'course' unless this is a technical term, which in that case leave it. 

However, in reality, only 54 species were caught in commercial bottom trawls with a fine mesh insert during 11 years of observations, of which only 20 were found in large numbers.

Perhaps rearrange this line as it is rather long. Either break them up (1) or rearrange them to make it shorter (2). Also remove the first coma. Not sure what the 'insert' functions as here, best to remove it unless it is the name of the mesh.

1) However in reality, only 54 species were caught in commercial bottom trawls with a fine mesh. During 11 years of observations, only 20 were found in large numbers.

2) However in reality, of the 54 species caught in commercial bottom trawls with a fine mesh, only 20 were found in large numbers over a period of 11 years.

Other than that the abstract seems fine.

I wish no one harm. I don't want anyone to get hurt. I hope nothing bad happens. It depends on context really.

A long day

Today was a long day.
I had to stay with the kids from this morning until five minutes ago. I was worried I would be bored, because after one or two hours with the kids, I need to be alone and relax. Not listening to screams, complaints or someone who is crying (that's why during the weekend, if I don't have to babysit, I go out for a walk or drink a cappuccino with a piece of cake - and that's why I am getting fat).
I am surprised, but it was a good day! Long, but not so bad as I thought.
In the morning, after having breakfast, we played to Monopoly together (without any fights) and then we went to the woods near the house. The kids found a lot of golf balls and they decided to give them to their father.
After lunch, and after an argument, we were able to watch a movie - we watched Paddington - and then played together.
Staying with the kids is not so bad, but now I am happy to stay in my room and watch a movie.

Note: I think the mistakes that you made are simply because of carelessness and can easily be solved by practice. All in all a very good and entertaining piece.

我学习汗液

我是第十三学校的学生。

我住在私厨。

我有狗。 You used the character for enough here.

我爱我的家。 我有爸爸，妈妈和妹妹。的 is a possessive particle, showing ownership. 家 is 'family'. 加 is 'to add'. 和 he2, second tone is 'and/и'.

我学习汗液

Just to be sure, you study at School Number 13? Not too sure where you live or what you study.