We went through a period _____ communications were very difficult in the rural areas.
A．which B．whose C．in which D．with which
I like getting up very early in summer. The morning air is so good ______.
A．to be breathed B．to breathe C．breathing D．being breathed
On the north of the bank _____ the Opera House, _____ was built two hundred years ago.
A．is lying; where B．lies; what C．lies; which D．lying; that
One learns a language by making mistakes and ________them
A．correct B．to correct C．to correct D．correcting
________ on the top of the hill, you can enjoy a good view.
A．Stand B．Stood C．Standing D．To stand
I wonder whether the soldier is one of those who _______ abroad to keep peace.
A．has been sent B．have been sent C．have sent D．has sent
