电容器的寿命与电压、电流及（）有关。A、电容 B、温度 C、容抗 D、电能

（15分）20世纪的战争与和平

材料  1965年美国总统约翰逊先后下令实施“火箭行动”计划和“滚雷”计划，对北越进行持续轰炸，派遣3500名海军陆战队员在岘港登陆作战，美国地面部队开始大规模进入越南南方作战。越南战争由“特种战争”扩大为“局部战争”。

在出兵援越的策略上，中国以派出防空、铁道、国防工程、筑路等支援部队形式介入战争，而且不公开宣布，并将支援部队的军事行动限制在越南北方。至1968年3月止，中国先后入越的部队共23个支队32万余人，其中最高年份达17万余人。而美国明知中国在大规模援越，中国支援部队在越南北方执行军事任务，也不予公开点破。

——《三八线与十七度线——朝战和越战期间中美信息沟通比较研究》

（1）根据材料概括中美两国在越南问题上的不同表现。（6分）

（2）根据材料并结合所学知识分别指出中国采取“有限援越”和美国明知实情却不“公开点破”的原因。（9分）

既能改善慢性稳定性心绞痛患者预后又可以减轻症状、改善缺血的药物是（）.

A.阿司匹林

B.β受体阻滞剂

C.硝酸酯类药物

D.钙拮抗剂

E.ACE抑制剂

The safety belt saved the boy; otherwise, he _____ in the accident.

A．would be killed

B．was killed

C．had been killed

D．would have been killed

阅读理解。

     Language is always changing. In a society where life continues year after year with few changes, the

language does not change, either. The earliest known languages had difficult grammar but a small, limited

vocabulary. Over the century, the grammar changed, and the vocabulary grew. For example, the English

and Spanish people who came to America during the sixteenth century gave names to all new plants and

animals they found. In this way, hundreds of new words were introduced into English and Spanish

vocabularies. Today life is changing very fast, and language is changing fast too.

     There are several major language families in the world. Some scientists say there are nine main families,

but other scientists divide them differently. The languages in each family are connected, and scientists think

that they came from the same parent language About 3 percent of the people in the world speak languages

that are not in these major families.

1. The early language had ______.

A. a lot of problems

B. words and easy grammar

C. words but no grammar

D. grammar but not many words

2. In the next few hundred years we can expect language to ______.

A. stay exactly the same

B. change a great deal

C. change only a little

D. add more words and drop some grammar

3. What this article shows is that ______.

A. languages change fast

B. languages really don't want to change

C. language changes with changes of society

D. Spanish and English change

4. From this article we can see that ______.

A. language can change very slowly or very quickly

B. if we don't change, then our language won't change, either

C. we should give our plants new names

D. English and Spanish are the only languages that have changes

《麦琪的礼物》中的女主人公为给丈夫买圣诞礼物，卖掉了

A．头发
B．祖传怀表
C．首饰
D．玳瑁发梳