---I called you last night, but nobody answered.
---Oh, I usually___off my cellphone by 9:00 p.m.
A．switched B．have switched C．switch D．had switched
---You aren’t looking well. Anything the matter?
---I’ve been surfing the net too long. I’m a bit tired.I can hold on,____.
A．though B．yet C．besides D．therefore
All of the things there are inexpensive, with prices ________ from about $1 to $10.
A．ranging B．changing C．distinguishing D．differing
the sentence , so he asked the teacher to explain it again.
A．Not having understood B．As he didn’t understand
C．Having not understood D．He didn’t understand
——The weather is too cold ____ March this year.
——It was still ____ when I came here years ago.
A．for; colder B．in; cold C．in; hot D．for; hotter
The “Warning” reads: “Under no circumstances _____ be kept near fire!”
A．the chemical should B．the chemical shouldn’t
C．should the chemical D．should the chemical not
