1.Contrary to popular belief, colds are not caused by exposure to severe weather.

2.The custom can be traced back to the roman era.

3.A more common belief is tips were first given in the 18th century England.

4.In America and Europe it is customary to tip anywhere from 10% to 20%.

5.Today most people decide the size of tip according to the quality of the service.

答案：

1.和人们的普遍想法相反，感冒并非恶劣的气候造成。

2.付小费这种习俗这种风俗可以追溯到古罗马时代。

3.付小费这种习俗源于18世纪的英国。

4.在美国和欧洲，人们普遍的做法是以消费金额的百分之十到百分之二十来付小费的。

5.现在，人们付小费的数量取决于享受的服务质量。