water pollution

I study water pollution.

私は水質汚染を勉強します

I study water pollution from books.

私は本で水質汚染を勉強します

I study water pollution from books at the weekend.

私は週末に本で水質汚染を勉強します

I study water pollution from books with my older brother at the weekend.

私は週末に兄と本で水質汚染を勉強します

I study water pollution hard from books with my older brother at the weekend.

私は週末に兄と本で水質汚染を一生懸命勉強します