() of the students in my class are girls.

思维程序

调查研究

验证假设

论证假设

uninteresting

noisy

tidy

fixed

fixing

to fix

to be fixed

转移

补偿

投射

退化

必须使用带ADDITIVE子句的SET RELATION命令

直接利用SET RELATION命令进行关联

在保持A→B关联的基础上不能再建立B→C关联

在保持A→B关联的基础上不能在建立的B→C关联，但可以建立A→C关联

设随机变量X,Y,Z相互独立，且X～N(1,2)，y～N(2,2)，Z～N(3,2)，如果（）

can we get

we can get

should we get

160

140

150

130

Air is (1) , and like all matter, it has weight. Weight is the measure of the (2) of gravity (3) matter. If a scale registers 10 kilograms when a stone is placed on it, this means that gravity pulls the stone with that (4) force. (5) , earth’ s gravity pulls on each (6) of gas and dust on the atmosphere. Because our atmosphere is a. vast (7) of air, it has (8) . If it could (9) be compressed and put on a (10) of scales, it would weigh about 5,700,000,000,000,000 (quadrillion) metric tons.

The air pressed down on us and against us (11) all sides. Something (12) a ton of air is pressing against you at this moment. You are not (13) of this because air pressure within your body (14) the pressure of the air outside.

Air pressure is 1. 036 kilograms per square centimeter (14.7 pounds per square inch) at sea (15) . It is greatest there because that is the (16) of the atmosphere. (17) higher altitudes the pressure is (18) . That is why the (19) of highflying planes are pressurized. They are designed to (20) the air pressure our bodies must have.

complied

convened

compiled

conveyed