阀门强度试验应按1.5倍公称压力的水压进行，试验时间不少于（）。 A.10min B

陆上运输货物战争险规定，如果被保险货物不卸离火车，则以火车到达目的地的当天午夜起计算，满（）小时为止。

A.24

B.36

C.72

D.48

用燃烧法除去密闭容器中空气成分里的氧气，应选择下列物质中的[ ]

A.细铁丝(Fe)

B.红磷(P)

C.硫粉(S)

D.木炭(C)

阅读理解

     Camels are large animals living in dry areas. There are two species of camels: the Arabian camel

with a single hump from the dry desert, and the Bactrian camel with two humps from Centraland East

Asia. Camels are over 7 feet tall and weigh over 1,600 pounds. They will live up to 40 to 50 years .

Most camels are domesticated(驯化)and fed by people. Camels are plant-eaters.

     Camels are very strong animals with wide, padded feet. They have thick leathery pads on their knees

and chest. Camels have nostrils(鼻孔)that can open and close, protecting them from the desert

environment. Bushy eyebrows and two rows of long eyelashes protect their eyes from sand. Their mouth

is extremely tough, allowing camels to eat thorny(带刺的)desert plants. Their widened feet help them

move without sinking into the sand. Their thick coats reflect sunlight, and also protect them from the

intense heat from desert sand. Their long legs help by keeping them further from the hot ground.

     Camels can go without food and water for 3 to 4 days. They do not store water in their humps as is

commonly believed. The humps are actually a container of fat. Camels are incredibly(难以置信)

well-adapted to their environment. When conditions heat up, camels can increase their own body

temperature, which prevents sweating and therefore water loss. They may not sweat at all during the day.

     Camels are sometimes called "ships of the desert" because people ride them around the hot, dry

deserts of the world. However, the number of camels is becoming smaller for various reasons.

1. According to the passage, camels usually live in           .

A. Asia

B. Africa

C. America

D. Australia

2. Paragraph 2 is mainly about           .

A. camels are useful animals

B. camels are clever animals

C. camels' body structure and function

D. camels' characteristics and habits

3. The reason why camels lose little water in deserts is that they           .

A. get water from green foods

B. can adjust their temperature

C. store enough water in the humps

D. can manage without water

4. What will the author probably talk about following the last paragraph?

A. Ways to protect camels.

B. Habitats of camels.

C. Reasons for raising camels.

D. Functions of camels.

在较高温度下，某溶液所含硝酸钾和氯化钠都已经接近饱和，当其冷却至室温时，析出的晶体经检验几乎不含氯化钠，这是因为 [ ]

A、氯化钠的溶解度比硝酸钾小

B、氯化钠的溶解度比硝酸钾大

C、氯化钠的溶解度受温度变化小

D、氯化钠的溶解度在室温时更大