Small sailboats can easily turn over in the water ________.

if not managed carefully

if are not managed carefully

unless not managed carefully

unless are not managed carefully

---Have you moved into        new office?

---No, the building is under          construction.

a; the

the; /

/; the

/; /

考查冠词。--你搬到新办公室了吗？--没有，大楼正在建设中。new office 谈话的双方都知道，所以是特指，需要用定冠词the,第二句under construction 指“正在建设中”，是固定搭配。故选B项。

Last night I had just gone to bed          an odd delivery man knocked on the window of my house.

as

before

when

while

考查状语从句引导词。句意：昨天晚上，我刚刚上床睡觉突然觉得一个奇怪的送货员敲我房子的窗户。固定搭配had  done sth when表示某人刚做完某事突然.....故选C项。

I would really appreciate       if you can make time in your schedules to attend my lecture today.

that

it

this

one

考查形式宾语。句意：如果你今天能从日程安排中抽出时间来听我的讲座的话，我将不胜感激。I would appreciate it if/when...如果/当...时，我将非常感激。it 做形式宾语。故选B项。

Only after my friend came ______.

did the computer repair

he repaired the computer

was the computer repaired

the computer was repaired

句意：直到我的朋友来了之后电脑才被修理。放于句首的only修饰时间状语从句after my friend came，主句应进行部分倒装，将助动词was提到主语前面，故选C项。