词汇。根据句意及首字母提示补全单词。

1.The old man was born in the 19th c_____.

2.You can t_____ the basketball from any part of the court.

3.I'll go s_____else.

4.Could you please give me a f_____?

5.Are you r_____? let's begin.

现有A、B、C、D四种金属，把A、B分别浸入稀硫酸中，产生气泡都很慢；把C、D 分别浸入稀硫酸中，产生气泡都很快；把A、B用导线连接时，A上有气泡逸出；把C浸入D的硝酸盐溶液中，C表面有D析出。这四种金属的活动性顺序由强到弱为 [ ]

A． C>D>B>A

B． C>D>A>B

C． D>C>A>B

D． D>C>B>A