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.

In the U.S. Congress, the House of Representatives and the Senate are ______.

A. not equal. The House is more powerful
B. almost equal in power
C. not equal. The Senate is far more powerful
D. different. The House is more important

女性，5岁。发现心脏杂音4年。查体：胸骨左缘2～3肋间可闻Ⅳ级粗糙SM，向上传导，可及震颤，P减弱。心电图示右室肥厚。

典型的心电图改变是（）

A.右室肥厚

B.左室肥厚

C.双室肥厚

D.一度房室传导阻滞

E.不完全右束支传导阻滞