Listening is thus an active, not a , behavior consisting of hearing, understanding and remembering.

A. considerate          B. sensitive

C. reliable            D. passive

In this article , you need to back up general statements with ________ examples.

A. specific             B. permanent

C. abstract              D. universal

His comprehensive surveys have provided the most__________statements of how, and on whatbasis, data are collected.

A. explicit              B. ambiguous

C. original             D. arbitrary

Generally，students' inner motivation with high expectations from others  ________  essential to their development.

A．is               B．are

C．was             D．were

The university estimates that living expenses for international students ________ around $8，450 a year, which ________ a burden for some of them.

A. are；is               B. are；are

C. is；are               D. is；is

In our class, when the bell rang and the teacher closed his book, it was a ______ for everyone to stand up.

A. signal          B. chance

C. mark               D. measure

Carbon dioxide, which makes a ________ between us and the sun, prevents heat from getting out of the atmosphere easily, so the earth is becoming warmer.

A．difference         B．comparison

C．connection         D．barrier

With inspiration from other food cultures, American food culture can take a  ________  for the better.

A．share             B．chance

C．turn             D．lead

I bought a dress for only 2010 dollars in a sale;it was a real.

A. exchange            B. bargain

C. trade                 D. business

The young man made a ______to his parents thathe would try to earn his own living after graduation.

A.prediction            B.promise

C.plan                 D.contribution