1. The house is very dirty. I haven’t cleaned it __________ yesterday.
A. for B. last C. ago D. since
2. Heavy rain during the night has caused floods __________ the country today.
A. throughout B. over C. all D. on
3. I’ve already seen this TV program. Can you change the __________ ?
A. theater B. channel C. television D. radio
4. He went on working __________ he was very tired.
A. because of B. although C. because D. in spite of
5. The department store has been in business __________ many years.
A. A. since B. for C. ago D. after
6. Watching TV is an ___________ way to relax.
A. enjoy B. enjoying C. enjoyable D. enjoyed