bothers me is that I can't keep my mind on the task, but on personal gains or losses.

What

It

That

One

考查主语从句连接词。句意：困扰我的是我不能专注于任务，而是专注于个人得失。此处为主语从句，从句中缺少主语，结合句意表示“困扰我的是”应用what。故选A项。

With a lot of difficult problems           ,he feels like a cat on  hot bricks.

to settle

being settled

settling

settled

考查非谓语动词。句意： 因为有一大堆难题要解决，他感觉像像热锅上的蚂蚁。本句with +名词+to do sth,动词不定式表示的动作尚未发生或当时看来尚未发生。本句表示“因为有一大堆难题要解决”。故选A项。

______about wild plants that they decided to make a trip to Madagascar for further research.

So curious the couple was

So curious were the couple

How curious the couple were

The couple was such curious

It’s his brother ______ never been to Australia. You’d better take him with you.

that is

who is

that have 　

 who has

句意：就是他的弟弟从没去过澳大利亚。你最好带他和你去。根据句意及题干分析此题是考查强调句型，因为强调的是his brother，是人，所以用who引导是现在完成时态，故选D。

In our daily life, everyone fails every now and then. It is how you             that makes a difference.

react

replace

rely

request

考查动词词义辨析。句意：在我们的日常生活中，每个人都会时不时地失败，你对失败如何反应才是关键。A. react反应；B. repalce取代，代替；C. rely 依靠，依赖；D.request要求；根据“n our daily life, everyone fails every now and then”，应是“怎样做出反应”。故选A项。

I have no one        me. for I am a new comer here.

help

helping

to help

to have helped

考查非谓语动词的用法。句意：我没让人帮我，因为我是新来的。根据句意可知句子空格处非谓语动词作定语，用了have sb /sth to do的结构,意为“让某人做某事”。故选C项。

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。