3.C　词义推测题。由第四段可知,“祖父悖论”指的是如果时间旅行者的祖父被杀,时间旅行者则不可能出生。

　　4.B　观点态度题。从全文看,无论是引用的两位科学家的观点,还是H.G.Wells书中的事例,都说明了作者对时间旅行持有怀疑态度,最后一段更是明确表明了作者的态度,故选B项。unclear “不清晰的”;skeptical“怀疑的”;supportive “支持的”;unconcerned “不关心的”。

　　二、语法填空(共10小题;每小题1.5分,满分15分)

　　Waiting for a bus can be very 1.(annoy).Often you have been at the bus stop for half an hour,and the bus still doesn’t come.2.,people in Zhongshan,Guangdong don’t have to suffer this.It’s all because of a mobile APP,Zhongshan Real-time Buses.With the APP,people can find out the exact time a bus arrives and set an alarm to remind 3.(them) to go to the bus stop in time. 

　　Five Senior 1 students make the APP possible.At first,they just wanted to add or change bus lines to help make it much 4.(easy) for students at their school to take buses.But later,they wanted to make something that is 5.(benefit) to all the people of Zhongshan.6.(get) technical support,the team turned to the local public transportation group company.They carried out three surveys by collecting questionnaires 7. are completed by about 600 people in shopping malls and bus stops.“The work took up almost all of our spare time for four months,” said Su Yinan,16. 

【2017届高考英语一轮复习知识梳理练习：选修7 Unit 21 Human Biology（北师大版）】相关文章：

★ 2017高考四川省广安市英语阅读理解一轮系列训练：8（含解析）

★ 【人教版】2014届高考英语一轮复习指导考点针对练：必修5 unit2《The United Kingdom》

★ 【浙江专用】2014届高考英语一轮复习课时作业(三十)选修6Unit 5《The power of nature》

★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (51)

★ 2017年高考英语二轮复习精品资料：专题14 阅读理解（押题专练）（原卷版）

★ 2017高考四川省广安市英语阅读理解一轮系列训练：11（含解析）

★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (64)

★ 【北师大版】2014届高考英语一轮复习指导课时作业：Unit 8 B卷 Word版含解析

★ 【北京专用】2014届高考英语一轮复习方案课时作业：必修5 Unit 4 Making the news

★ 2017届高考英语二轮复习书面表达限时测验：2（含解析）