单项选择题.Mr. Smith, I should tell you this is the fifth time you me for my twin sister.
单项选择题Scientists are convincedthe positive effect of laughterphysical and mental health.
单项选择题Now in China many young peopleimportant positions in the government.
单项选择题Information obtained from libraries is sooner forgotten than .
单项选择题Personally, I prefer to stay upat night, but notIll have to drive to work the next day.