Maybe they are not in the library.(同义句转换)
Theyin the library..
Dick is watching Tv now.(用sometimes改写句子)
Dick sometimes.
I believe chickens can swim.(改为否定句)
I                  chickens        swim.
They did it two days ago.(对划线部分提问)
                       they       it?
I eat junk food two or three times a week.( 对划线部分提问)
do you eat junk food?
To sleep for eight hours every night is important.( 同义句转换)
to sleep eight hours every night.
You should eat some Chinese medicine.(改为否定句)
You          eat         Chinese medicine.
The boy didn't stand up before the teacher came in.( 同义句转换)
The boy         stand up          the teacher came in.
she, what, doing, vacation, is, for, week, next?(连词成句)
？