第10题: [单项选择]The flower bud of a water lily opens at sunset since its opening is triggered by the decreased light. A. alleviated B. endured C. set off D. covered op 参考答案:C 答案解析:trigger引发,触发。set off使开始。alleviate使(苦痛等)减轻。endure耐久,忍耐。Cover up掩盖错误、非法地事物等。
第15题: [单项选择]Which of the following is true about Olson A. He was a fiction writer. B. He edited the book Power and Prosperity. C. He taught economics at the University of Maryland. D. He was against the ownership of private property. 参考答案:C 答案解析:第一段最后一句Olson was an economics professor at the University of Maryland until his death in 1998.Olson一