未焊透

控制下颌运动的因素不包括（）

A.右颞下颌关节

B.左颞下颌关节

C.牙齿的咬合接触关系

D.神经、肌肉

E.血管、淋巴

亚当•斯密在《国富论》（1776）中曾有如下描述：“一个人抽出金属丝，另一个人拉直，第三个人切断，第四个人削尖，第五个人打磨顶部做出头；……用这种方法，做一枚别针的工序被分为18个单独的操作程序。”这主要反映了

A．万能蒸汽机极大提高了社会生产力

B．工人独立完成生产的能力大幅下降

C．手工工场中生产的复杂化和低效率

D．工厂制度下对劳动过程的合理组织

D

The Internet has become part of teenage life.

A new report on 3,375 students aged from 10 to 18 in seven Chinese cities found that 38 percent of them believe they use the Internet often.

While most of them get useful information and use the Internet to help in their studies, some are not using it in a good way.

In order to help young people use the Internet in a good way, a textbook on good Internet behaviour (行为) has started to be used in some Shanghai middle schools this term. The book uses real examples to teach students all about good ways of using the Internet. The book gives useful advice such as it’s good to read news or find helpful information to study.

Some students also make online friends. But if you are meeting a friend offline, make sure your parents know. Teachers and parents all think the book is of great help. A teacher said the book would be a guide for teens using the Internet. She believes it will keep students away from bad sites. “Many students are using the Internet without guidance from their parents,” she said. “The book will teach students how to be a good person in the online world.”

68. The textbook mainly tells us ______.

A. why we should use the Internet    B. how to study using the Internet

C. how to use the Internet correctly   D. how to get help from others

69. What’s the attitude of teachers and parents towards the textbook?

A. They are against it.               B. They are for it.

C. They don’t care about it.          D. The passage doesn’t mention.

70. According to the passage, teenagers are NOT encouraged to ______.

A. read online news          B. go online 

C. find helpful information online

D. meet a friend offline without letting their parents know

71. From this passage we know that _______.

A. more and more students have given up visiting bad Web sites

B. schools and teachers begin to pay attention to students’use of the Internet

C. no more homework will be given in Shanghai middle schools

D. less and less information can be found on line

华支睾吸虫慢性严重感染者导致的后果是（）

A.胆石症伴胆绞痛

B.出现精神症状

C.门脉性肝硬化

D.顽固性黄疸

E.消瘦、贫血、乏力

柴油机喷油器调压弹簧弹力减弱或断裂后，将使（）。

A.喷油时间无变化

B.喷油时间延迟

C.喷油时间提前

D.喷油量增多