什么有的线路装设过电流保护，不装设速断保护？

读等高线地形图，回答下列问题：

（1）图中大青山顶峰的海拔是______米，小青山顶峰的海拔是______米，大青山顶峰比小青山顶峰高______米．

（2）图中甲地坡度比乙地______，原因是______．

（3）图中比例尺改用文字式表示，图上1厘米代表实际距离______千米．

（4）填出以下代码表示的地形部位名称：

AB线是______，CD线是______，

丙处是______，丁处是______．

在妊娠晚期羊水过少的诊断标准是（）

A.100ml

B.200ml

C.300ml

D.400ml

E.500ml

Like many other aspects of the computer age, Yahoo began as an idea, (1) into a hobby and lately has (2) into a full-time passion. The two developers of Yahoo, David Filo and Jerry Yang, Ph. D candidates (3) Electrical Engineering at Stanford University, started their guide in April 1994 as a way to keep (4) of their personal interest on the Internet. Before long they (5) that their homebrewed lists were becoming too long and (6) . Gradually they began to spend more and more time on Yahoo.

During 1994, they (7) yahoo into a customized database designed to (8) the needs of the thousands of users (9) began to use the service through the closely (10) Internet community. They developed customized software to help them (11) locate, identify and edit material (12) on the Internet. The name Yahoo is (13) to stand for "Yet Another Hierarchical Officious Orale", but Filo and Yang insist they selected the (14) because they considered themselves yahoos. Yahoo itself first (15) on Yang’s workstation, "akebono", while the search engine was (16) on Filo’s computer, "Konishiki".

In early 1995 Marc Andersen, co-founder of Netscape Communication in Mountain View, California, invited Filo and Yang to move their files (17) to larger computers (18) at Netscape. As a result Stanford’s computer network returned to (19) , and both parties benefited. Today, Yahoo (20) organized information on tens of thousands of computers linked to the web.

3（）

A.in

B.on

C.about

D.for

垂柳可以吸收有害气体问这种有害气体是什么？

（）是维护膝关节正常功能的主要结构。

A、肱骨

B、胫骨

C、腓骨

D、髌骨