40． Prices of daily goods _____ through a computer can be lower than store prices.

A. are bought       B. bought       C. been bought       D. buying

41． Don’t use words, expressions, or phrases _____ only to people with specific knowledge.

A. being known       B. having been known 

C. to be known        D. known

42． Unless ____ to speak, you should remain silent at the conference.

A. invited               B. inviting  

C. being invited          D. having invited

43． Friendship is like money: easier made than _____.

A. kept          B. to be kept      C. keeping      D. being kept

44． Mr. Smith, ____ of the _____ speech, started to read a novel.

A. tired; boring    B. tiring; bored    C. tired; bored   D. tiring; boring

45． _____ time, he’ll make a first-class tennis player.

A. Having given   B. To give     C. Giving            D. Given