The computer system ________ suddenly while he was searching for information on the Internet．

broke down

broke out

broke up

broke in

This kind of coat ________ very well．

doesn’t sell

has been sold

isn’t sold

isn’t being sold

His car ________ on the way to school．

broke out

broke down

broke in

broke up

The doctor ________ is leaving for Africa next month．

the nurse is talking to him

whom the nurse is talking

the nurse is talking to

who the nurse is talking

A geographer might be described ________ one who observes, records, and explains the difference between places．

for

as

to

by

It is the letter that I got, not what you’ve told me, ________ makes me sad．

which

what

that

when

We can hardly imagine him ________ the hard work alone．

to finish

finishes

in finishing

finishing

Let’s ________ turns to look after the patients．

make

take

get

do

He spent all his free time he has ________ his classmates．

to help

helped

helping

help

I have some ________ the English grammar．

difficulties in understanding

difficulties to understand

difficulty understanding

difficulty to understand