90. At the age of _______, he had his own lab.

　　 A. thirty　　　 　　 B. thirtieth 　　 　C. the thirtieth　　 D. the thirty

89. --- What is 1/2 and 1/3?　　 --- It’s _______.

　　 A. 2/5　 　　　 B. 1/5　 　　　　　　　 C. 5/6　 　　　　　　　 D. 4/6

88. We are sure the _______ century will bring us more hopes.

　　 A. twentieth-first 　 B. twentieth-one　　 C. twenty-one　 　　 D. twenty-first

87. We will have a _______ holiday. What about going to Suzhou?

　　 A. five days 　 B. five day　　　　　　 C. five-day　　 　　 D. five-days

86. --- How soon will you finish your work?　　 --- In about _______.

　　 A. one and a half month 　B. one month and a half　 C. one and half a month 　D. a month and half

85. February 28 should be read as _______.

　　 A. February of the 28th 　　　 B. February of 28　 C. 28 of February D. the 28th of February

84. The flood happened _______.

　　 A. in the summer of 1998　　 B. in the summer of 1998s

　　 C. in 1998 of the summer　 　D. in 1998s of the summer

83. My lovely daughter is _______.

　　 A. eight years old　 　B. eight-year-old　　 C. eight year old　　 D. eight-years-old

82. Boys and girls, we are going to learn _______ today.

　　 A. Four Lesson　　 B. the fourth lesson　　 C. the Lesson Four　 　D. the Four Lesson

81. There are _______ people in my family. We live on the _______ floor in a tall building.

　　 A. five, six　　 　B. fifth, sixth　　 C. fifth, six　　 D. five, sixth