【题目】--- I can’t carry the luggage．It’s so heavy.

【题目】According to a recent survey, homework is what students most often ________ for their lack of sleep.

【题目】—I have studies gardening as one of my hobbies. Could I make some suggestions?

【题目】Training of the employees was suggested as one _____ to dealing with the problem of low efficiency.

【题目】---You were brave enough to raise objections (反对) at the meeting.

【题目】With our knowledge ________ practice，we can make great contributions to our society.

【题目】He is ______ a teacher to me, and he is also my friend.

【题目】I am sorry, but I didn't mean to keep you waiting here so long. Can you ________ me?

【题目】---Tell us, Mark, what is the cause of the American Civil War?

【题目】At the end of the holiday, traffic_______ on the freeway as people headed home.