根据句意及首字母提示补全单词。

1. China's flag has five yellow s_________ on it.

2. Beijing is in the n_________ of China.

3. Wang Fei is a very f_________ singer in China.

4. I want to v_________ Buckingham Palace some day.

5. I can't fly a kite (放风筝). It's not e_________, I think.

患者，男性，25岁，体检发现右肾重度积水。

如果要排除单纯性肾盂扩张可能，可选择的方法是（）

A.卡托普利试验

B.利尿试验

C.乙酰唑胺试验

D.多巴酚丁胺试验

E.双嘧达莫试验