She drew up a chair close _______ the be.

A.drawn

B.was drowned

C.dawn

D.down

A.works up

B.fills up

C.stirs up

D.builds up

A.She said lttle ，only answering briefly when others asked her a question.

B.She said lttle， when others asked her a question， she only answered briefly.

C.She said lttle， only answering briefly when asked a question.

A.她本想凶狠地回答一下说再也不想生孩子了，可话到了舌尖又收回去了，只是笑了笑。

B.她本想尖锐地回答一下说再也不想生孩子了，可话刚到舌尖她又及时抓住自己，只是笑了笑。

C.她本想狠狠地回敬一下说再也不想生孩子了，可话到嘴边又停住了，只是笑了笑。

(1)求静态工作点和跨导;

(2)画出微变等效电路，并求电压放大倍数、输入电阻和输出电阻。

(3)若C_S=0，重复(2)的计算。

LM1877N-9为2通道低频功率放大电路,单电源供电,最大不失真输出电压的峰峰值U_opp=(V_cc-6)V,开环电压增益为70dB.图P9.14所示LM1877N-9中一个通道组成的实用电路,电源电压为24V,C₁~C₃对交流信号可视为短路;R₃和C₄起相位补偿作用,可以认为负载为8Ω.

(1)图示电路为那种功率放大电路？

(2)静态时u_p、u_N、u_o、u_o各为多少？

(3)设输入电压足够大,电路的的最大输出功率P_om和效率ƞ各为多少？

Read the following passage and the statements that follow. Choose the best answer for each statement from the three choices marked A, B and C .

Outdoor Learning Environment

“How do they get the tomato on the vine(藤、蔓)？”

The question shocked Hillis. It reminded him of the time five years ago when he was volunteering at Beattie Elementary School in his daughter’s kindergarten classroom. He’d been reading the children a book about gardening.

“These kids had only seen vegetables in supermarkets,” he says. “I felt that something important was missing in their lives.”

So he went to work. Hillis and his wife, Sally, made the local government believe that it was necessary to create an outdoor learning environment. He and other volunteers raised more than 30,000 dollars to make such a project. The project was designed like the Platte River. Like the river, the school’s front walkway turns east to west, so they planted things along the walkway, such as native grasses which can be found along the river too.

Today, students are greeted every day by the cedar-mulched creation(雪松覆盖的表面), which spreads the length of three city blocks. In the back, there’s a garden, with twenty 1 ton rocks lying in the ground, where teachers hold classes.

The outdoor effort has changed things inside, too. For science, children plant seeds and, based upon each seed’s size and weight, guess how large a vegetable will grow to become. For arts and crafts, they collect fallen leaves and make designs out of them. Other science lessons make up a large part of the outdoor learning process. “No matter what time of the year it is,” Hillis says, “there’s always something going on.”

1.Hillis was a volunteer at Beatte Elementary School five years ago().

A.Right

B.Wrong

C.Doesn’t say

2.Halloween was first celebrated by the()around the fifth century.

A.English

B.American

C.Irish

D.European

3. The purpose of this course is to make the students know various rules of English grammar().

A.True

B.False

C.Not Mentioned

4.Students can tell how large a tomato will grow to become according to the seed’s size().

A.Right

B.Wrong

C.Doesn’t say

5.Craftsmen need knives and gravers of various types to make complicated patterns().

A.Right

B.Wrong

C.Doesn’t say

6. Which of the following doesn’t belong to the western culture()？

A.Europe

B.North Africa

C.Asia

D.America

7. What is the author’s main idea in the text()？

A.Education can be purchased

B.The difference between education and schooling

C.Degree is worthless

D.Students should learn more important knowledge

8. The settlers also taught the Indians to penetrate the forest, to hunt large animals().

A.True

B.False

C.Not Mentioned

9.The passage is mainly about().

A.parts of the brain that store information

B.illness that results in serious memory loss

C.how human brains process, store and recall information

D.how to improve our memory

10.What do you think “ginseng and gingko” probably are()？

A.Plants

B.Animals

C.Food

D.Drinks

11.Halloween happened().

A.from October 31st to November 1st

B.on October 31st

C.on November 1st

D.between October 31st and November 1st

12. How many cultural differences does the author mention in the text()？

A.One

B.Two

C.Three

D.Four