发射结正向偏置，集电结正向偏置，则此三极管工作在（）状态。

第二部分：阅读理解（共25小题；每小题2分，满分50分）

第一节 阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该项涂黑。

Ever since she was a baby, Heather, aged 5, has watched her parents regularly turn off lights

that aren’t needed and put the day’s newspapers cans, bottles, jars, and other recyclables into a big, yellow bin — that is, if they can't find a second life for the discarded items in their own home first. Plastic packaging, pieces of cardboard, scraps of colored paper, bits of yarn, and small pieces of broken toys are typically dropped into a basket that the whole family rummages through whenever they need supplies for an art project. Recently, after spying a bit of shiny paper on the floor, Heather picked it up and said, "This is pretty. I'll put it in the art basket." Already, like parents, like daughter.

Heather's effort to recycle a scrap of paper rather than throw it away is a tiny gesture with a big message. It shows that even young children can learn about conserving materials and resources, and by extension, protecting the planet, in age-appropriate ways. It also shows that your child is so tuned in to your ways that it is easy to become an environmental role model. But because children are more apt to want to care for something they have a personal stake in, it's as important to expose your child to the natural world as it is to teach her ways to protect it.

This doesn't require week-long camping trips into the wilderness — although those can be fun, enlightening experiences for the whole family. Children can explore, appreciate, and learn about nature literally in their own backyard, in a park, in a community garden, and on trips to the beach or mountains. There's more good news: Giving your child opportunities to connect with nature can also help her develop crucial literacy, language, math, science, social studies, art, problem-solving, and research skills.

41．The underlined word “discarded” (Paragraph 1) probably means “___________.”

A．waste       B．important  C．small D．dirty

42．Which of the following statements is true according to the text?

A．The family is quite poor.

B．The family members don’t waste any money.

C．The parents are proud of saving materials.

D．The parents set an example to the daughter.

43．The text mainly suggests that children___________.

A．love recycling things         B．are curious about things

C．can learn to protect nature      D．should act the way as their parents

44．What’s the author’s suggestion about introducing a child to the natural world?

A．Going on a camping trip.          B．Traveling to the wilderness.

C．Learning from their parents.   D．Playing in such places as a park.

有关生物一心理一社会医学模式的描述正确的是（）

A.心身是二元的

B.起源于17世纪

C.根源于三个主要发现

D.美国心身医学家恩格尔提出的

E.当前西医占主导地位的医学模式

关于肺结核病下列哪项是错误的：（）

A.继发性肺结核好发于锁骨上下区（指从胸片上看）

B.链霉素和卡那霉素联合应用好

C.原发型肺结核易于血行和淋巴管播散

D.观察结核菌素试验反应应在注射后15分钟判断结果

E.慢性纤维空洞型肺结核无传染性

社会主义经济建设自改革开放以来所取得的令人瞩目的成就应该说与理论界和经济学家的突出贡献是分不开的，但这不应该成为要求理论界和经济学家独立承担起改革重任的理由。历史和现实已经在召唤社会学家、政治学家、文化学家以及经济学家共同参与到中国的改革理论与改革实践中去。 这段话的中心思想是( )。

A．理论界和经济学家为社会主义经济建设作出了巨大的贡献

B．社会主义经济建设取得了令人瞩目的成就

C．历史和现实要求各方面的专家、学者共同参与到中国的改革理论和改革实践中

D．中国的改革理论与改革实践是艰巨的

lac操纵子有（）个结构基因。

A、两个

B、三个

C、四个

D、五个