设等差数列{an}的公差d大于0,a1=9d,若ak是a1与a2k的等比中项,则

题型:选择题

问题:

设等差数列{an}的公差d大于0,a1=9d,若ak是a1与a2k的等比中项,则k=[ ]

A.2

B.4

C.6

D.8

考点:等差数列的定义及性质等比中项
题型:选择题

A young woman was driving through the lonely countryside. It was dark and rainy. Suddenly she saw an old woman by the side of the road, holding up her hand as if she wanted a lift(搭便车).

"I can't leave her out in this weather," the young woman said to herself. She stopped the car and opened the door.

"Do you want a lift?" she asked. The old woman nodded(点头) and climbed into the car. After a while, she said to the old woman, “Have you been waiting a long time?" The old woman shook (摇晃) her head. "Strange!" thought the woman. She tried again. "Bad weather for the time of year," she said. The old woman nodded.  Then the young woman noticed the old woman's hands, which were large and hairy(多毛的). Suddenly she realized that "she" was a man! She was frightened at first. Then she stopped the car. "I can't see out of the rear screen(挡风玻璃) ,"she said. "Would you mind cleaning it for me?"

"The old woman" nodded and opened the door. As soon as "she" was out of the car, the frightened young woman drove off as fast as she could.

When she got to the next village, she stopped. She noticed "the old woman" had left "her" handbag behind. She picked it up and opened it. Inside was a gun(枪)

小题1:When the young woman talked with "her", "the old woman" only nodded or shook "her" head because "she"_______.

A.didn't want the young woman to hear "her" voice

B.didn't want to trouble the young woman any more

C.was so tired that "she" didn't want to talk with her

D.wondered if the young woman had seen "her" hands小题2: How did the young woman find “she” was a man?

A.The young woman hared her "voice"

B.The young woman saw a gun in the handbag

C.The young woman noticed the old woman’s hands were big and fairy

D.The young woman had never seen "the old woman"小题3:The young woman asked "the old woman" to clean the rear screen in order to________

A.see more clearly

B.drive fast and well

C.make "her" speak

D.throw "her" out小题4:From the story we can see that the young woman was______.

A.kind and clever

B.beautiful and bright

C.foolish and shy

D.strong and helpful小题5:What do you think "the old woman" was________.

A.A policeman.

B.A basketball player.

C.A robber

D.A poor villager

题型:选择题

2014年广州市马拉松比赛没有经过()景点

A、花城广场

B、猎德大桥

C、人民公园

D、人民桥

题型:选择题

计算平均发展速度通常用( )。

A.算术平均法

B.几何平均法

C.众数

D.中位数

题型:选择题

根据《行政处罚法》的相关规定,合法的行政处罚构成要件有()

A.处罚主体合法

B.处罚程序合法

C.未超越、滥用职权

D.适用法律法规正确

E.事实清楚、证据确凿

题型:选择题

病毒灭活冰冻血浆在留取标本前应置30~37℃融化,融化时间应小于几分钟()

A、5

B、10

C、3

D、6

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