选择题：相应于任意确定的基准面，土中的总水头H包括（ ）(本题2.0分) A、 势水头 B、 势水头+静水

14. According to the passage, dogs and cats.A. can see colors as well as human

37.The power which an engine develops is ________ to the wheels.A. transmitted

关于索引，以下叙述正确的是 A)主索引和唯一索引都能保证表记录的惟一性B)在数据库表和自由表中都可建立侯选索引C)建立索引后，将根据索引表达式的值重新排列记录，

45. To ________ his position in Parliament, he held talks with leaders of the P

15. Which of the following is not true about insects?A. Insects can see more co