So difficult __________ it to work out the problem that I decided to ask Tom for advice.

 I did find 

did I find

 I have found  

have I found

句子使用的基本句式为so…that…结构。按英语语法，当该结构的so…置于句首时，其后的句子(主句)要用倒装语序，如：So loudly did he speak that even people in the next room could hear him. 他讲话声音那么大，隔壁屋里的人都听得见。

Really? You        twice the price to buy the book!

paid

took

spent

cost

考查动词词义辨析。句意：真的吗？你付了2倍的价格买这本书！四个动词都有“花费”的意思，但用法不同。pay的主语通常是人，常用结构是 sb pay (money) for sth;take作“花费”时讲常用于固定句型 It takes/took sb (money/time)to do sth做某事花费某人（金钱/时间）；spend的主语通常是人 sb spend...on sth 或sb spend ...(in) doing sth;cost的主语通常是物，sth cost sb (money)意为“某物花了某人多少钱。本题主语是人，结合句意和后文to buy the book，空格处应填pay。故选A项。

The exhibition           next Sunday will feature paintings created by contemporary artists.

hosted

being hosted

to be hosted

hosting

考查非谓语动词。句意：下星期举办的展览将展出当代艺术家的作品。根据句意及分析句子结构可知，此处表示将来发生的事情，应使用不定式作定语，host 与 exhibition 之间是逻辑动宾关系，应使用不定式的被动式。故选C项。

The black teacher set a good example ____ all the rest of the group, _____ all peace-loving people.

to, who are

for, which was

to, which are

to, who were

[翻译]黑人教师给其他所有爱好和平的人树立了一个好榜样。[解析] D 解析：set an example to表示给某人树榜样，由此可以排除B;因先行词指人，故使用who引导非限定性定语从句，由此可以排除C; 根据时态的一致原则可知，此处应当使用一般过去时，故正确答案为D项。

True happiness does not            the possession of money, but the joy of achievement.

contribute to

lie in

result in 

add to

考查动词短语辨析。句意：真正的幸福不在于拥有钱，而在于成功的喜悦感。contribute to有助于；lie in 在于；result in 导致；add to增加。结合语境可知，此处指“真正的幸福不在于有多少钱”。故选B项。

---I'm sorry,but it's my seat.

---           I didn't know it's yours.

What if

I beg your pardon

That's all right

What for

考查交际用语。句意：---对不起，这是我的座位。---请原谅。我不知道这是你的。A. What if如果.....将会怎么样；B. I beg your pardon. 对不起，请原谅；C.That's all right没关系；D. What for为什么。根据"Idon't know it's yours."可知坐了别人的座位，请求别人原谅。故选B项。