辅扇调节的使用方法有（）。A.带风墙的辅扇 B.不带风墙的辅扇 C.调节风窗面积

With the help of the collected money, subways can be built sooner and better, _______ brings convenience to citizens.

A．as

B．what

C．who

D．which

The following questions present a sentence, part of which or all of which is underlined. Beneath the sentence, you will find five ways of phrasing the underlined part. The first of these repeats the original; the other four are different. If you think the original is best, choose the first answer; otherwise choose one of the others.

These questions test correctness and effectiveness of expression. In choosing your answer, follow the requirements of standard written English; that is, pay attention to grammar, choice of words, and sentence construction. Choose the answer that produces the most effective sentence; this answer should be clear and exact, without awkwardness, ambiguity, redundancy, or grammatical error.

During the bronze sculpture boom of the late 1950s, more than 20 tons of bronze were shipped to the SoHo district of Manhattan so as they might sculpt countless bronze statues, busts, abstract shapes, and whimsical figurines.（）

A. so as they might sculpt

B. in order that they might be sculpted into

C. so that there could be sculpted

D. for the sculpting of

E. such that they could be sculpted into

认识反应规律，控制反应条件，让化学反应为人类服务．

（1）化学小组的同学利用图12所示的装置探究燃烧的条件．

①通过对比铜片上红磷和白磷的不同现象，得出的结论是　                               　．

②小明同学对以上实验进行概括，得出的下列说法中，不正确的是　 　（填字母序号）．

A．此组实验烧杯中的热水只起提高温度的作用

B．图1中水下白磷未燃烧是由于没有与氧气接触

C．对图1实验应该进行三组对比分析

D．若将图2中白磷换成红磷，不能观察到燃烧现象

（2）A常用于切割金属．在点燃条件下，A和B反应能生成C和D．反应前后分子变化的微观示意图如图3所示．

①下列说法正确的是　               （填字母序号）．

A．该反应属于放热反应          B．A物质具有可燃性

C．化学反应前后原子的种类不变  D．该反应属于置换反应

②该反应中A与B的质量比是　          　．

③该反应过程中，若提高B物质的浓度及用量，好处是　             　．

什么是“傻瓜水稻”？

熔池的几何尺寸与焊接工艺参数、母材性质、坡口形状和尺寸无关。