博士英语考题中的几道选择题，高手帮忙选择一下正确答案，并把四个选项分别翻译一下意思啊。谢谢!

Question

1.the cycle of the tide occures twice every 24 hours and is _on the moon
A .evident B. depengdent C.indenpent D.subsequent
2. It is not necessary to boil the drinking water, because it has already been_chemically.
A\distilled B.cleared C .purified D.refined
3\The river is already _its banks because of excessive rainfall and the town is threatened with a likely flood
4\ The space Age_in the Oct 1957 when the first artificial satellite was launched by the Soviet Union.
A.embarked B.initialed C.commenced D. originated
不好意思、3的选项忘了写了。如下：
A level in B.flat on C.parallel to D.flush with
四个选项的词最好能依次翻译一下啊。

Answer 1

1.the cycle of the tide occures twice every 24 hours and is _on the moon
A .evident B. dependent C.indenpent D.subsequent
选 B
A. evident, 形容词，明显的，用法是 be evident to/ that 从句
B. dependent,形容词，两层意思：1，依赖的，依靠的；2，取决于。用法是
be dependent on

2. It is not necessary to boil the drinking water, because it has already been __ chemically.
A.distilled B.cleared C .purified D.refined

选 C

3.The river is already __ its banks because of excessive rainfall and the town is threatened with a likely flood.
A level in B.flat on C.parallel to D.flush with
选 D

4.The space Age __ in the Oct 1957 when the first artificial satellite was launched by the Soviet Union.
A.embarked B.initiated C.commenced D. originated

选 B

Answer 2

cdbb

Answer 3

acdb