1. --- It's time for bed, Mary.
--- Oh, Mum, I can't go to bed I haven't finished my homework.
A. so B. until C. since D. if
2. Everyone should protect our environment, so it's necessary not to trees.
A. put away B. cut down C. pick up
3. --- Hi, Tom, why so unhappy?
--- I missed the exciting match the bad traffic.
A. in order to B. since then C. as a result D. because of
4. Monica, you the exam! Congratulations!
A. pass B. have passed C. will pass D. are passing
