All the characteristics that distinguish birds ________ other animals can be traced to prehistoric times..
A. to B. between C. for D. from
Mother made a promise ________ I passed the exam, she would buy m e a computer..
A. if B. that C. that if D. whether
He tried his best, but he couldn’t ________ the college entrance exams last year.
A. get through B. get over C. get up D. get away
Because of my poor English I'm afraid I can't make myself ____．
A．understand B．to understand C．understanding D．understood
I really appreciate that your help is of great _________.
A. useful B. value C. important D. worth
He insisted that we ________ rest until we finish the work.
A. not B. don’t C. can’t D. should
