It is _________ popular way among the young people to chat on the Internet now．

a

an

the

My sister isn’t in．_________ she comes back, I’ll let her call you back．

While

Until

Before

When

Not only Lucy’s brothers but also Lucy herself _________ living in China now．

enjoy

enjoys

enjoying

enjoyed

Everyone is here．Let’s _________ our class now．

begin

began

beginning

to begin

As students, we _________ study hard to make our country more beautiful and stronger．

should

may

can

could

We will have finished _________ Unit 15 by April．We can review all the lessons．

learning

learn

learned

to learn

He is _________ to make money to support his parents．

old enough

enough old

young enough

enough young

The population of China is _________ than that of any other country in the world．

large

small

larger

smaller

The bell is ringing．Hurry up, _________ you’ll be late for class!

and

but

while

or

Wang Lin reads books at the school library _________ the afternoon every day．

of

on

at

in