某医院有内科医生12名，外科医生8名，现选派5名参加赈灾医疗队

（1）某内科医生甲与某外科医生乙必须参加，共有多少种不同选法？

（2）甲、乙均不能参加，有多少种选法？

（3）甲、乙两人至少有一人参加，有多少种选法？

（4）队中至少有一名内科医生和一名外科医生，有几种选法？

用所给动词的适当形式填空 .

1. I am against _____ (build) a new zoo in our city.

2. Don't worry.  All the little tigers _____ (take) good care of in the zoo.

3. _____ (collect) waste paper and bottles in the park is our duty.

4. We saw your brother _____ (throw) rubbish here just now.

5. We _____ (visit) a lot of famous zoos in the world so far.

6.         _ (not spit) everywhere.  You must keep the environment clean.

7. Some animals _____ (keep) in the zoo. I think it is not good for them.

8.  We find zoos are not suitableplace for animals _____ (live) in.

9. Many animals are only _____ (give) food once a day.

10. If we don't support our zoo, they _____ (have) enough money to take care of so many fine animals.