我们食用的蒜黄，其叶片是黄色的，这是因为培育时（） A．缺乏肥料 B．没有见光

阅读理解。

    Do you know how to play a game called "Musical Chairs"? It is easy to play and most people enjoy it. All

you need are some chairs, some people and some way of making music. You may use a piano or any other

musical instrument, if someone can play it. You may use a tape recorder. You can even use a radio.

    Put the chairs in a row. The chairs may be put in twos, back to back. A better way is to have the chairs

in one row with each chair facing in the opposite direction to the chair next to it.

    The game is easy. When the music starts, the players walk round the chairs. Everyone goes in the same

direction, of course, they should walk in time to the music. If the music is fast they should walk quickly. If

the music is slow, they should walk slowly.

    The person playing music cannot see the people in the game. When the music stops, the players try to sit

on the chairs. If a person cannot find a chair to sit on, he drops out. Then, before the music starts again, one

chair must be taken away. When the music stops again, one more player will be out.

    At last, there will be two players and only one chair. The one who sits on the chair when the music stops

is the winner.

1. If ten people are playing musical chairs, you must begin with _____. [ ]

A. nine chairs

B. ten chairs

C. eleven chairs

D. one chair

2. Which of the following may be unacceptable according to this article? [ ]

A. A piano

B. A radio

C. A violin

D. A telephone

3. When the music starts, the players must _____. [ ]

A. run about the room

B. get down

C. walk around the chairs

D. sit on the chairs

4. Which of the following statements is NOT true? [ ]

A. The game "Musical Chairs" is not difficult to learn.

B. The last one can't sit on the last chair.

C. The winner can sit on the chair.

D. If the person plays music, he cannot be the winner.

鸡的正常粪便呈（），表面覆有一层白霜状的尿酸盐沉淀物，且有一定硬度。

A、灰绿色

B、黄白色

C、黄绿色

D、暗黑色

下列哪项不是免疫组织化学染色中修复抗原的方法？（）

A.冷冻

B.水浴加热

C.高压加热

D.微波加热

E.蛋白酶消化

肾后性急性肾衰常见的原因是

A．上呼吸道感染
B．严重挤压伤
C．双侧输尿管结石
D．药物中毒
E．缺水、血容量减少

简述专利权的内容及限制。