The rapidly growing birth rate brings about a lot of environment problems, which the government is supposed to take _____.
Speak to him slowly _____ he may understand you better.
You'll miss the train ______ you hurry up.
When you read the book, you' d better make a mark _____ you have any questions.
We'd better hurry ______ it is getting dark.
I didn' t manage to do it _____ you had explained how.