问题 选择题

工业酒精中含有甲醇(CH3OH),若误食可能会中毒、致眼失明.下列关于甲醇的说法中,错误的是(  ) 

①甲醇由四种元素组成   

②甲醇分子由一个碳原子、四个氢原子和一个氧原子构成   

③一个甲醇分子共含有六个原子  

④甲醇分子中C、H、O原子个数比为1:4:1.

A.③④

B.①②

C.①④

D.②③④

答案

①根据甲醇的化学式CH3OH 可知:甲醇由碳、氢、氧三种元素组成,故①说法错误;

②根据甲醇的化学式CH3OH 可知:一个甲醇分子由一个碳原子、四个氢原子和一个氧原子构成,故②说法错误;

③根据甲醇的化学式CH3OH 可知:一个甲醇分子共含原子个数是1+4+1=6,故③说法正确;

④根据甲醇的化学式CH3OH 可知:甲醇分子中C、H、O原子个数比为1:4:1,故④说法正确.

故选B.

阅读理解

阅读理解。

     Imagine that you are the first person ever to see Hawaii. What would be the first thing you would set

foot on?

     The beach, naturally. There are hundreds of miles of beaches on the twenty islands of Hawaii. These

islands cover l,600 miles and are about 2,300 miles west of California. Most of them are covered with fine

white sand. They are thought to be among the finest beaches in the world.

     Another wonderful thing about the beaches of Hawaii is the water temperature. The year-round average

(平均) temperature of the water at the famous Waikiki Beach is 23℃!

     The same is true of air temperature. In fact, there are no real seasons in Hawaii. There is a difference of

only two or three degrees between the hottest day of summer and the coldest day of winter. That's why the

Hawaiians don't have a word for weather in their language.

     Perhaps the nicest thing about Hawaiian beaches are the waves. The earliest settlers (定居者) in Hawaii,

the Polynesians, quickly leamed how much fun it was to ride the waves. They developed a sport which is

now very popular on the islands called body surfing. You go out into the ocean, wait for a big wave to come

towards you, jump on it, and ride it all the way to the beach.

     Now imagine once again that you are the first person ever to set foot in Hawaii. What do you think would

be the second beautiful thing you would notice? Would it be those strange triangles ( 三角形状物) rising out

of the water hundreds and hundreds of meters high? What are those beautiful things? They are volcanoes (火山), of course. These volcanoes are not just a part of the islands. They made the islands at first. Because of

them the islands are still growing.

     The most famous volcano on Hawaii is Mauna Loa. It is the world's most active volcano. It has been

erupting (喷发) for thousands of years. Even when it isn't erupting, smoke comes out of the earth from a

thousand little holes.

     In 1950 Mauna Loa erupted for twenty-three days. That erupting produced the greatest amount of lava (熔岩) in modem history. In 1960 it erupted again. That time it added a kilometer of beach to the island. Because

Mauna Loa has erupted so often, it has become the biggest (but not the tallest) mountain in the world.

     These volcanoes could be dangerous to the population of Hawaii. In fact, hello, the second largest city in

Hawaii, is built just under Mauna Loa. The volcano could erupt at any time. Most people believe that it will

erupt sometime in the next twenty-five years. But the people of Hilo do not seem worried. They live with the

danger as part of their lives.

1. According to the passage, what are the two most beautiful things in Hawaii?

A. Waves and cities.

B. Beaches and language.

C. Volcanoes and beaches.

D. Volcanoes and people.

2. Which is NOT the reason why the Hawaiians don't have a word for weather in their language?

A. There are no real seasons in Hawaii.

B. The temperature of the water at one of the beaches is always 23℃.

C. The Hawaiians feel almost the same in the hottest day and coldest day.

D. There is not much difference in air temperature all the year round in Hawaii.

3. What should be the meaning of "body surfing"?

A. Riding waves.

B. Body-building.

C. Sea bathing.

D. Jumping into the sea.

4. It can be inferred that _______ according to the passage.

A. volcanoes are more active because the area of the island is enlarging

B. the visitors to Hawaii can probably see more than one active volcano

C. Mauna Loa is the tallest mountain in the world because it has erupted so often

D. people in Hilo are sure that more visitors will come because of volcanoes

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