If you want to catch the first bus you'd better         for the bus station immediately.

set up

set about

set down

set off

考查动词短语辨析。句意：如果你想赶上第一班公交车，你最好马上动身去车站。A. set up建立；B. set about开始做.....;C. set down 记下；D. set off 出发，动身。结合上文If you want to catch the first bus you'd better可知此处指“动身，出发”，应用set off。故选D项。

--What is happening in that new area?

---New houses          over there.

are built

are building

have built

are being built

考查时态和语态。句意：在那个新区域里发生什么事情了？那儿建起来许多新的大楼。根据第一句时态is happening 可知，时态用现在进行时，故第二句也要用现在进行时，主语 houses与build 建立之间是被动关系，故用现在进行时的被动语态（am/is/are being done），此处为are being built，故选D项。

I thought we'd be late for the concert,           we ended up getting there ahead of time.

but

or

so

for

考查连词。句意：我以为我们音乐会迟到了，但是我们提前到达了那里。but 但是；or 或者；so 因此；for因为；两个分句在意义上bu是转折关系，故用but。故选A项。

The number of deaths from a powerful typhoon sweeping across China’s east coast          to 30 on Sunday.

raised

rose

aroused

arose

考查动词词义辨析。句意：周日，异常席卷中国东海岸的强台风造成的死亡人数上升到30人。A.raised提升，增加； B.rose 增加（原形是rise）C.aroused激起，引起；D.arose发生，出现。分析句子可知，这里要表达“人数增长到30”，而A,B选项中，raise是及物动词，后面直接接宾语，而rise为不及物动词，用“rise to”表示“增长到.....”。故选B项。

It was along the Mississippi River _________ Mark Twain spent much of his childhood.

how

which

that

where

此处构成It was...that...强调句式，句中强调了介词短语along the Mississippi River。故选C。