问题 选择题

“x>2”是“x2>4”的(  )

A.充分不必要条件

B.必要不充分条件

C.充要条件

D.既不充分也不必要条件

答案

当x>2时,x2>4成立,

故“x>2”⇒“x2>4”为真命题

故“x>2”是“x2>4”的充分条件;

当x2>4时,x<-2或x>2,即x>2不成立

故“x2>4”⇒“x>2”为假命题

故“x>2”是“x2>4”的不必要条件;

综上“x>2”是“x2>4”的充分不必要条件;

故选A

听力题

单词拼写(共10小题;每小题1分,满分10分)

请将单词的完整形式写在题后所给的横线上。

81. The city is s________ (位于) on the west bank of Mississippi river.    81. ________________

82. One of the basic needs in many d________ (发展中的) countries

is water.                                                                                     82. ________________

83. The wind blew more and more v________ (猛烈地).                        83. ________________

84. Children should be educated to be good c________ (公民).                84. ________________

85. Confucius is the philosopher whose i________ (影响) has been

the greatest.                                                                                 85. ________________

86. The report p________ (预测) that the more jobs would be lost

in the coal industry.                                                                             86. ________________

87. You should ask for a r________ (收据) when taking a taxi.                87. ________________

88. I only wear this suit for f________ (正式的) dinners.                        88. ________________

89. We s________ (支持) the police strongely in their work against crime.      89. ________________

90. The H1N1 viruses are u________ (不可能) to lead to large numbers

of deaths.                                                                                           90. ________________

选择题