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问题 选择题
若{an}为等差数列，Sn是其前n项和，且S11=
22π
3
，则tana6的值为（　　）
A．
3
B．-
3
C．±
3
D．-
3
3
答案

∵S11=

11(a1+a11)
2
=11a6=
22π
3

∴a6=

2π
3

∴tana6=-

3
，

故选B．

单项选择题 A3/A4型题

女，35岁。已拔除3个月，要求作固定义齿修复，经查对颌无明显伸长，相邻牙牙周健康，拔牙创已完全愈合。

患者要求修复美观耐用的义齿，应选的固定桥设计为（）

A、3/4冠固定桥

B、开面冠固定桥

C、嵌体冠固定桥

D、烤瓷冠固定桥

E、塑料冠固定桥
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单项选择题

It was a very hot day in the middle of summer, and there were no trees along the street. Mr. Read (41) his shop at half past five, and went out into the street and began walking to the bus. He was a very (42) man. The sun shone straight down the street, and in a few minutes Mr. Read (43) very hot.

A. pleasedB. OK C. sorry

A small boy came out of another (44) in the street and followed Mr. Read. He stayed very (45) him all the time, and he kicked Mr. Read’s (46) several times. Mr. Read looked at him angrily each time.After the fourth time, Mr. Read stopped, turned (47) and said to the small boy, "What are you doing (48) following me like that! You’re going to hurt my feet."
"I’m (49) , but don’t stop me, please!" the small boy said. "It’s very hot today, and there isn’t (50) shade anywhere else in the street!\
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