下面几个数中，一个0都不能去掉的是（ ） A．2.0080 B．0.20080 C．0

某套利者卖出4月份铝期货合约，同时买入5月份铝期货合约，价格分别为19670元/吨和19830元/吨，平仓时4月份铝期货价格变为19780元/吨，则5月份铝期货合约变为（）元/吨时，价差是缩小的。

A.19970

B.19950

C.19980

D.19900

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.
Microwave communication uses high-frequency (26) waves that travel in straightlines through the air. Because the waves cannot (27) with the curvature of the earth, they can be (28) only over short distance. Thus, microwave is a good (29) for sendingdata between buildings in a city or on a large college campus. For longer distances, the waves must be relayed by means of "dishes" or (30) . These can be installed on towers, high buildings, and mountain tops.

A．transmitted

B．transformed

C．converted

D．delivered

去极化肌松药的作用与下列哪类药物作用类似（）

A.筒箭毒碱

B.新斯的明

C.抗胆碱酯酶药

D.乙酰胆碱

E.阿托品

IMO船舶操纵性衡准中推荐的标准试验法包括下列哪些？（）

A.旋回试验、Z形试验、初始回转试验、停船试验、螺旋试验和回舵试验

B.旋回试验、Z形试验、初始回转试验、停船试验、逆螺旋试验和回舵试验

C.旋回试验、Z形试验、初始回转试验、停船试验、倾斜试验和螺旋试验

D.旋回试验、Z形试验、初始回转试验、倾斜试验和回舵试验

铁路组织卸车，在卸车时应做到哪些？