阅读理解。
根据短文内容。判断下列句子的正误。正确的用“T”错误的用“F”。(每小题1分。共5分)
Most people in America speak only one language: English. They do not learn to speak a second language.
High schools teach languages. But why?
First, most Americans never travel to other countries. America is a very large country. Americans can
travel a long distance and not leave the United States. Why don't Americans speak other languages? They do
not need to learn a second language.
Second, one of the countries next to America is Canada. Most people in Canada speak English. Some
Americans live near Canada. They travel there often. But they do not have to learn a new language.
Third, many people in other parts of the world speak English. If Americans travel to other countries, they
can speak English there, too.
Some Americans think that it is a mistake to speak only English. They believe it is very important to learn a
second language. Maybe someday other Americans will agree. Then more people will speak a second language
in America.
( )1. Most Americans never learn to speak a second language.
( )2. Many Americans like traveling to other countries except Canada.
( )3. In other parts of the world many people speak English.
( )4. Some Americans think it is a mistake to travel to other countries.
( )5. Many Americans find it difficult for them to learn a second language.
的核反应中，要 （填“吸收”或“放出”）2.22 Mev的能量，核反应过程中的质量亏损为 kg．（保留两位有效数字）