.Slang words (俚语) are made _____ special groups,such as workers and musicians.
Lu Xun was ___________ medical student before he turned ___________ great writer.
— These boxes are too heavy for me to carry. — Here, I’ll give you a hand ________ them.
They said the building would be completed ________ a year.
We should divide all the potatoes ________ two piles and separated the good ones ________ the bad ones.
The weather this month has been good ________ .