In the factory, the helmets the workers wore varied _____ color according to their different posts.
The river ________ are covered with trees is very long.
The film which _______ the book by Jack London is well worth seeing.
I won’t allow him to make the trip alone, even if he_____ do it.
He asked me, “Did you see my sister last night?” ----He asked me __________
______ the bad weather, the children had to stay home all day.