小光在修理电子玩具时，需要用一个24Ω的电阻，现在手边有阻值为10Ω、14Ω、1

加氢催化剂经长期使用后，随着催化剂表面（）的增加，活性将逐渐下降，以致不能满足生产上的要求，此时需对催化剂进行（）。

本人或监护人提出申请城乡特殊困难未成年人教育救助后，由（）调查核实。

A.乡镇政府

B.城市街道办事处

C.县级民政部门

D.村委会（社区居委会）

Are you nervous about climbing because you think it’s too dangerous? Do you feel you’re not fit enough to climb? Do you know how to start climbing?

Let’s consider the idea that climbing is dangerous. Being afraid is natural, but if you use suitable ropes and other climbing equipments you will feel completely safe. Climbers are usually very careful because they know what they are doing is dangerous. Accidents happen, but when they do, they tend to attract a lot of publicity. As a result, people think there are many more accidents than there are in reality.

You cannot expect to start climbing straight away. Climbing is a challenge and challenges take time. It is necessary first of all that you achieve a good level of fitness. Begin as soon as you become interested in climbing—go to the gym, go swimming, take up jogging and continue to do so throughout your training period.

Discover as much as you can about climbing. Visit the library and find books especially for beginners or buy climbing magazines and look for articles which describe your situation. Look up information on the Internet. Find out about equipment, methods and places to go.

Next, take a course on a climbing wall. There are plenty of climbing walls all over the country which have trained and qualified people as instructors. Call your local leisure centre to find out if there is one in your area. These training sessions are a quick way to get experience and you are likely to meet other beginners. After this, you can do an outside course or join a club where you can meet climbers of all abilities and eventually join in group-climbing events.

At first you may not understand the importance of a good training period, but after you have completed your first climb and you are standing safely at the top of a rock feeling thrilled, then you will know it was the right thing to do.

小题1:The article is written by ______.

A．a doctor

B．an experienced climber

C．a beginner

D．a fitness instructor小题2:The writer thinks a new climber should ______.

A．begin by becoming fit

B．be aware of the causes of the accidents

C．have the courage to meet the challenges

D．do enough sports to get interested in climbing小题3:By climbing walls you can ______.

A．join a club you like

B．become qualified instructors

C．gain controlled experience

D．take part in group-climbing events小题4:The underlined word “it” in the last paragraph probably means ______.

A．the climb

B．the training

C．the equipment

D．the achievement

当Esc键与单击该命令按钮作用相同时，此命令按钮的什么属性被设置为 Tree

A． Style

B． Default

C． Caption

D． Cancel

某框架剪力墙结构，框架柱间距9m，楼盖为梁板结构。第三层楼板施工当天气温为35℃，没有雨。施工单位制定了完整的施工方案，采用商品混凝土。钢筋现场加工，采用木模板，由木工制作好后直接拼装。其施工过程如下：模板安装用具有足够强度和风度的钢管做支撑，模板拼接整齐、严密。楼面模板安装完毕后，用水准仪抄平，保证整体在同一个平面上，不存在凹凸不平的问题。钢筋绑扎符合规范要求。但是，施工现场没有设计图纸上按最小配筋率要求的HPB300钢筋（φ12200），需要用其他钢筋代替。施工单位经与监理工程师及业主，决定用HRB335的钢筋代替，按等强度折算后为φ12250，以保证整体受力不变。钢筋验收后，将木模板中的垃圾清理干净，就开始浇筑混凝土。浇筑前首先根据要求取足够的试样，送试验室进行试验。之后开始浇筑混凝土，振捣密实。10d后经试验室试验，混凝土试块强度达到设计强度的80%，起过了75%，施工单位决定拆除模板。拆模后为保证结构的安全性，在梁的中部、雨篷外边缘、楼梯等处采用局部临时支撑。拆模后发现：

（1）梁板挠度过大，起过了规范的要求；

（2）混凝土局部有蜂窝、麻面现象，个别部位形成空洞；

（3）楼面混凝土局部有开裂现象。

对于跨度为9m的现浇钢筋混凝土梁、板，底模及支架拆除时的混凝土强度应达到设计的混凝土立方体抗压强度标准值的百分率（%）为（）。

A.25

B.50

C.75

D.100