necessary surveys (which is) based on the problems。

9．The first time you take part in a race，________is very normal to feel tense.

A．which B．what C．that D．it

答案　D

解析　考查it的用法。句意为：第一次参加比赛，你感到紧张是很正常的。it在此作形式主语，真正的主语是后面的不定式to feel tense。

10．I haven't decided on the menu yet，let alone ________ the food.

A．buying B．to buy C．bought D．buy

答案　C

解析　句意为：我还没决定吃什么菜呢，更不必说买食物了。let alone意为"更别提，更不用说"，后跟与前面部分相对应的谓语或名词。这里前面部分是完成时态，所以用过去分词。

11．I wouldn't pursue my writing career now if I________ myself as weak in writing when I was young.

A．defined B．should define

C．would define D．had defined

答案　D

解析　考查虚拟语气。句意为：在我年轻的时候，如果我认定自己在写作方面薄弱的话，我现在就不会追求我的写作生涯了。根据时间状语可知，if从句是与过去事实相反的假设，谓语用had done。

12．Let's hold a party to________ your birthday and at the same time ________you on your passing the driving test.

A．congratulate；celebrate B．celebrate；celebrate

C．celebrate；congratulate D．congratulate；congratulate

答案　C

解析　句意为：让我们举办一个聚会庆祝你的生日，同时祝贺你通过了驾照考试。celebrate sth.庆祝某事；congratulate sb. on祝贺某人......。故C项正确。

13．He found it very difficult to speak________，for his lips trembled and refused to form the words.

A．plainly B．closely