[单项选择](Neither) rain (nor) sleet nor (keep) the mailman from his (appointed) rounds.
A. Neither
B. nor
C. keep
D. appointed

[单项选择](Neither) rain (nor) sleet nor snow (keep) the mailman from his (appointed) rounds.
A. Neither
B. nor
C. keep
D. appointed

[单项选择]Acid rain


A. immediately kills trees and affects aquatic life in lakes and rivers.
B. deposits various metals iron, mercury, aluminum into the soil.
C. kills forests by weakening them and reduces fish populations.
D. releases sulfur dioxide, nitrogen oxide and into the atmospher

[单项选择]

What makes it rain Rain falls from clouds for the same reason anything falls to Earth. The Earth’s gravity pulls it. But every cloud is made of water droplets or ice crystals. Why doesn’t rain or snow fall constantly from all clouds The droplets or ice crystals in clouds are exceedingly small. The effect of gravity on them is minute. Air currents move and lift droplets so that the net downward displacement is zero, even though the droplets are in constant motion.
Droplets and ice crystals behave somewhat like dust in the air made visible in a shaft of sunlight. To the casual observer, dust seems to act in a totally random fashion, moving about chaotically without fixed direction. But in fact dust particles are much larger than water droplets and they finally fall. The average size of a cloud droplet is only 0. 0004 inch in diameter. It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it does not fall out of mo
A. They never occur.
B. They are not affected by the force of gravity.
C. In still air they would fall to earth.
D. In moving air they fall at a speed of thirty-two miles per hour.

[单项选择]What makes rain fall

[单项选择]—There has been no rain for months. Will it rain soon
—（　）. The crops are in great need of water.
A. Of course
B. I hope so
C. I think so
D. I'm afraid not

[单项选择]Neither you nor he （）right.
A. are
B. would
C. am
D. is

[单项选择]Neither he nor I （） from Canad
A. We are from Australia.A. is
B. are
C. am
D. be

[单项选择]His wife speaks neither English nor French.


A. 他妻子既会说英语也会说法语。
B. 他妻子既不会说英语也不会说法语。
C. 他妻子不会说英语，但会说法语。
D. 他妻子会一点英语，也会一点法语。

[单项选择]Which of the followings is neither expressed nor implied in the passage as being a threat posed by mall to wildlife preservation


A. The discharge of chemical wastes into streams as a result of industrial development.
B. Large - scale housing development.
C. Poor coordination of international efforts at park and refuge management.
D. Introduction of species into environments.

[单项选择]Which of the following does NOT characterize a normal patent


A. some extension of life span
B. some duration of validity
C. some form of reward
D. some kind of monopoly