凝汽器铜管排列方法有几种，国产大型机组采用哪种管束布置？

Congress makes the laws in the United States. It has two pans, which are more or less equal in power. They are known as the House of Representatives and the Senate. The House of Representatives is larger than the Senate whose 100 members (two from each state) serve for six years. The 435 members of the House are elected every two years, and the number from each state is determined by the population of the state. For example, California, which has a large population, has 43 representatives, while the State of Nevada has only one.

The House and Senate are divided into small groups which take care of special matters such as education or foreign affairs. The most important work of Congress is often done in these groups, which are called subcommittees.

According to the Constitution of the United States, a senator must be at least 30 years old and he must have been a citizen of the United States for nine years at the time of his election. To be elected to the House a person must be 25 years old and must have been a United States citizen for seven years. At the present time, members of Congress include businessmen, farmers, teachers, and especially lawyers. In general, senators are better known than representatives because they are fewer in number and serve for a longer time. Many American presidents served in Congress before they became president.

The members of the Senate are elected for()years.

A. two

B. three

C. four

D. six

汽油不仅是重要的燃料，而且是重要的化工原料，可以通过汽油裂解得到化工原料如乙烯等，还可以在催化剂作用下改变汽油分子的结构，由链烃变为芳香烃，这种变化叫做异构化。下面是以石油为原料发生的有机物的衍变关系图：

（已知：反应③，④中的原子利用率均为100%）

请回答下列问题：

（1）上述反应①～⑦中属于加成反应的有___________________（填序号，下

同），属于取代反应的有__________________。

（2）写出A，B的结构简式：A______________，B________________。

C的分子式为_________________。

（3）写出下列反应的化学方程式：

④________________________________________________________________；

⑦________________________________________________________________。

马钱子须炮制后入药，其炮制的目的是（）

A.提高疗效

B.改变药性

C.减缓毒性

D.便于贮藏

E.便于制剂

下列各项，不属于专利申请类型的是（）

A.食品专利

B.外观设计专利

C.实用新型专利

D.发明专利