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问题 选择题

所谓的大脖子病是缺什么（　　）

A．生长激素

B．缺钙

C．缺碘

D．肾上腺激素

答案

A、生长激素能促进生长发育，幼年过多患巨人症，幼年过少患侏儒症，成年过多患肢端肥大症．A错误．

B、缺钙易患佝偻病和骨质疏松，B错误．

C、碘是形成甲状腺激素的主要成分，缺碘影响甲状腺的生长和分泌，引起肿大，也叫大脖子病，C正确．

D、肾上腺素过多，人易激动、心跳加快等，D错误．

故选：C

单项选择题

The usual way to ensure reliable delivery is to provide the (71) with some feedback about what is happening at the other end of the line. Typically, the protocol calls for the receiver to send back special (72) flame bearing positive or negative (73) about the incoming frames. If the sender receives a positive acknowledgement about a frame, it knows the frame has arrived safely. On the other hand, a negative acknowledgement means that’ something has gone wrong, and the frame must be transmitted again.

An additional complication comes from the possibility that hardware troubles may cause a flame to (74) completely. In this case, the receiver will not react at all, since it has no any reason to react. It should be clear that a protocol in which the sender transmits a frame and then waits for an acknowledgement, positive or negative, will hang forever if a frame is ever lost due to, for example, (75) hardware.

（72）处应填（）。

A．data

B．control

C．request

D．session
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(2007年普通高等学校夏季招生考试英语（北京卷）)C

Lying in the sun on a rock, the cougar （美洲狮） saw Jeb and his son, Tom, before they saw it. Jeb put his bag down quickly and pulled his jacket open with both hands, making himself look big to the cougar. It worked. The cougar hesitated, ready to attack Jeb, but ready to forget the whole thing, too.

Jeb let go of his jacket, grasped Tom and held him across his body, making a cross. Now the cougar’s enemy looked even bigger, and it rose up, ready to move away, but unfortunately Tom got scared and struggled free of Jeb.

“Tom, no!” shouted his father.

But Tom broke and ran and that’s the last thing you do with a cougar. The second Tom broke free, Jeb threw himself on the cougar, just as it jumped from the rock. They hit each other in mid-air and both fell. The cougar was on Jeb in a flash, forgetting about Tom, which was what Jeb wanted.

Cougars are not as big as most people think and a determined man stands a chance, even with just his fists. As the cougar’s claws（爪子）got into his left shoulder, Jeb swung his fist at its eyes and hit, hard. The animal howled（吼叫）and put its head back. Jeb followed up with his other fist. Then out of the comer of his eye, Jeb saw Tom. The boy was running back to help his father.

“Knife, Tom,” shouted Jeb.

The boy ran to his father’s bag, while Jeb started shouting as well as hitting, to keep the cougar’s attention away from Tom. Tom got the knife and ran over to Jeb. The cougar was moving its head in and out, trying to find a way through the wall Jeb was making out of his arms. Tom swung with the knife, into the cougar’s back. It howled horribly and ran off into the mountains.

The whole fight had taken about thirty seconds.

63. Why did Jeb pull his jacket open when he saw the cougar?

A. To get ready to fight.              B. To frighten it away.   C. To protect the boy.    D. To cool down.

64. What do we know about cougars?

A. They are afraid of noises.                                     B. They hesitate before they hit.

C. They are bigger than we think.                             D. They like to attack running people.

65. How did Jeb try to hold the cougar’s attention?

A. By keeping shouting and hitting.                          B. By making a wall out of his arms.

C. By throwing himself on the cougar.                      D. By swinging his fists at the cougar’s eyes.

66. Which of the following happened first?

A. The cougar jumped from the rock.                        B. Tom struggled free of his father.

C. Jeb asked Tom to get the knife.                                   D. Jeb held Tom across his body.
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