We need to repair the house before it rains, _______?
It is often said that ____teachers lead _______very busy life. A /, / B. /, a C. the, / D. the, a
—I’m going to play soccer now.—________. It’s raining heavily outside.
No one has yet succeeded in solving the _____ of how life first began.
Can you tell me ______?
—She looks very happy. She ______ have passed the exam.--I guess so. It’s not difficult after all.