问题 单项选择题

某山区发生了较大面积的森林病虫害。在讨论农药的使用时,老许提出:“要么使用甲胺磷等化学农药,要么使用生物农药。前者过去曾用过,价钱便宜,杀虫效果好,但毒性大;后者未曾使用过,效果不确定,价格贵。”
从老许的提议中,不可能推出的结沦是()。

A.如果使用化学农药,那么就不使用生物农药

B.或者使用化学农药,或者使用生物农药,两者必居其一

C.如果不使用化学农药,那么就使用生物农药

D.化学农药比生物农药好,应该优先考虑使用

答案

参考答案:D

解析:

老许的提议为不相容选言命题“要么使用化学农药,要么使用生物农药”,即两种农药只能选择一种。B项与题干意思相同;A、C两项也都能从题干推出;老许并没有确定哪种药更好,故不能推出D项。

单项选择题
阅读理解

My 10-year-old Donna said, “Mom, I made a new friend at school today. Can she come over tomorrow?” Donna was a shy girl and I wanted her to make some friends to bring her out of her shell.

“Sure, honey, that sounds great.” I said, thinking back to my own best friend, Lillian. We lived across the street from each other in Washington Heights, New York. We met at the age of 10, too. Like my daughter, I was shy, but Lillian drew me out. She was one of the friendliest people in school, with shiny black hair and a mile-wide smile.

In senior high school, Lillian went on a trip to Florida. This was the first time we had to be away from each other for a few days. “I’ll be back soon.” she told me. But three days later, Lillian’s sister told me that she had fallen into a river and hadn’t come out any more. Soon, my family moved to New Jersey. Whenever I thought of her, tears came into my eyes.

The next day Donna brought her new friend home. “Hi, Mrs. Loggia.” the little girl said. Her hair was so shiny and black and she shot me a big smile. “My name is Laura.”

My daughter’s new friend was so much like Lillian. I was still puzzled (迷惑) when Laura’s mom came to pick her up later that afternoon. I opened the door to let her in. “Judy!” she cried. “It’s me, Lillian’s sister, from Washington Heights.” Yes, my daughter’s friend looked familiar. She was Lillian’s niece.

小题1:The underlined words in the first paragraph “to bring her out of her shell” mean ___________.

A.to help her become less shy

B.to help her become smart

C.to help her live happily

D.to help her walk out of her house小题2:Laura looked familiar to the writer because she ____________.

A.was Lillian’s niece

B.was as old as her daughter

C.was from Washington Heights

D.had shiny black hair and a big smile, too 小题3:Why did the writer lose her best friend?   Because ____________________.

A.she moved to New Jersey

B.they were different from each other

C.her best friend travelled to Florida

D.her best friend lost her life on a trip小题4:“I knew we would be best friends forever.” is a sentence from the passage and should be put at the end of _______.

A.Paragraph 2

B.Paragraph 3

C.Paragraph 4

D.Paragraph 5小题5:We can infer (推断) from the passage that______.

A.Laura is outgoing

B.Laura helps Donna a lot

C.Laura and Donna are of the same age

D.Judy moved to New Jersey because of Lillian’s death