A: Someone is at the door.B: __________?
A. What is it?
B. Who is it?
C. Who is he?
D. Which one is it?
查看答案
I find ____________ to make some changes.
A. it is quite necessary
B. that is quite necessary
C. it quite necessary
D. quite necessary
A solar day is the length of time _________ the Earth to revolve once around the sun.
A. takes
B. takes it
C. it takes
D. taking
___________ from the sun _________ we get light and heat.
A. It is ... that
B. It was ... that
C. It must be ... that
D. It can be ... that
-- Who is making so much noise?-- ________ must be the children.
A. They
B. There
C. These
D. It
微信支付 
支付宝支付