主族元素X、Y、Z的离子为aX+、bY2—、cZ—，半径大小关系是aX+Z C．

出口商品经商检机构检验、口岸查验或者抽查检验不合格的，不准销售。( )

Scientists are developing a new kind of machine to take the place of humans. These machines can do jobs in places that are too dangerous for humans. For example, they are being developed to work in nuclear power center, deep under the oceans and in outer space.

John Marrit, a psychologist(心理学家) in Williamsburg Massachusetts, helped develop the new machine. This is how they work. A machine is placed in an area far away from the person who operates it. The person wears special hard hat with television screens and sound equipment. The screens and sound equipment let the person see and hear exactly what the machine is seeing and hearing. Mr. Marrit says this gives the person the feeling of being in the same place as the machine. The idea, he says, is being there without going there. The person uses an electronic control to make the machine move. The machine copies the person’s movements exactly. If the person raises his right arm, the machine raises the right arm, too. This means an expert can do a dangerous job while staying in the safe place. For example, a person can direct the machine to destroy a bomb without going near the bomb himself.

小题1:The new kind of machine being introduced in the passage is _______.

A．in existence

B．only an idea

C．being tried out

D．being researched and developed小题2:The machine _______.

A．follows the person’s order

B．is controlled by a computer

C．does exactly what the person does

D．is controlled by a television on the person’s head小题3:The difference between such a new machine and a robot is that _______.

A．the new machine is more difficult to make than a robot

B．the new machine is more difficult to be controlled

C．a robot is controlled by man indirectly

D．a robot can’t be used in places too dangerous or faraway

造成餐饮市场具有层次性的主要因素是（）

A.餐饮需求是人类的基本需求

B.不同地区消费者的消费习惯的差异性

C.餐饮消费者收入及消费心理需求的不同

D.餐饮市场环境变化

在土方工程中，土的含水量对（）均有影响。

A．挖土难易

B．降水方法

C．边坡稳定

D．填土压实

优秀服务代表的职业化形象塑造包括四个方面，其中不包括的是（）。

A.标准的职业形象

B.专业的服务技巧

C.标准的礼貌用语

D.标准的礼仪形态