The thief used a ladder that had been _________ by some workmen, and climbed over the wall．

A．left aside

B．left behind

C．left off

D．left alone

When I entered the room, I found Mary _________ at the desk _________ her homework．

A．sat; doing

B．sitting; to do

C．seating; to do

D．seated; doing

Yesterday we visited a modern hospital, around _________ some fruit shops．

A．which is

B．that is

C．which are

D．it are

The library’s study room is full of students ________ for the exam．

A．busily prepared

B．busy preparing

C．busily prepare

D．are busily preparing

Before radio and TV, music could only be heard ________, that is, you had to go to places where musicians gave performances．

A．live

B．alive

C．living

D．lively

________ you may have, you should gather your courage to face the challenge．

A．However a serious problem

B．What a serious problem

C．However serious a problem

D．What a serious problem

I thought of him as my best friend until he ________ to the boss．

A．gave me off

B．gave me out

C．gave me away

D．gave me up

________ we’ll be able to drive a car ________ by electricity, solar energy in about ten years．

A．Fortunately; driven

B．Eventually; power

C．Luckily; commanded

D．Hopefully; powered

The chickens will provide us ________ feathers, ________ we can make use for cleaning the table and benches．

A．with; with

B．with; of which

C．of; which

D．of; from which

The ancient Chinese vases ________ display attracted lots of experts and collectors, some of whom suggested they ________ on the next fair．

A．on; displayed

B．on; be displayed

C．in; displayed

D．in; be displayed