I was really too busy with my homework and I couldn't help ____________ housework.

A. doing        B. do               C. did          D. done 

I just don't understand_____________ that prevents so many Americans from being as happy as one might expect.

A. why it does                  B. what it does   

C. what it is                   D. why it is

The policy of the mainland is very clear and straightforward，and the key problem is ______ the leaders of Taiwan will accept it.

A．thatB．how  C．whyD．whether

The woman teacher hurriedly left the classroom as though ______.

A．angry

B．angrily

C．anger

D．being angry

______ two giraffes，Zheng He later brought zebras，shells，elephant ivory back to China after his voyages.

A．Besides thatB．Except   C．In addition D．Apart from

Don't ______.You will ______ new customs and different ways of thinking.

A．lose your heart；apply to

B．lost heart；apply yourself to

C．lose your heart；adapt to

D．lose heart；adapt yourself to

Generous public funding of basic science would______a good many benefits for the country's health，wealth and security.

A．result from   B．lead to  C．lie in   D．settle down

The price of houses ______ from 200 000 to 300 000 pounds in the suburb of London during this winter.

A．changedB．ranged

C．separatedD．differed

—Why are most of us unable to study English well，Mr.Li?

—You ______.But you ______ too little attention to it.

A．could；pay B．will；attach

C．would；referD．can；devote

I sat until after eleven，______in a book.

A．absorbing

B．having absorbed

C．absorbed

D．having been absorbing