问题 选择题

节日里的下列景象伴随有化学变化的是

A.五光十色的焰火礼花

B.不断闪烁的霓虹灯

C.变化无穷的音乐喷泉

D.满屋飘香的茅台酒

答案

答案:A

题目分析:化学变化是指有新物质生成的变化,物理变化是指没有新物质生成的变化,化学变化和物理变化的本质区别是否有新物质生成。

A、燃放烟花的过程中,生成了新物质二氧化碳、二氧化硫等物质,属于化学变化;

B、霓虹灯闪烁的过程中,只是稀有气体通电发光,没有新物质生成,属于物理变化;

C、音乐喷泉变化的过程中,只是水柱形状的变化,没有新物质生成,属于物理变化;

D、茅台酒飘香的过程中,只是分子的运动,没有新物质生成,属于物理变化。故选A

点评:解答本题的关键是,要会分析变化过程中是否有新物质生成,如果有新物质生成就属于化学变化,如果没有新物质生成就属于物理变化。

阅读理解

Sharks frighten most of us, but Daniel Weaver, a shark scientist, swims with them for a living! We asked him some questions about this unusual job.

So Daniel, what’s it like to be a shark scientist?

Well, it’s a great job. I often travel to faraway places like South Africa and Fiji to study sharks. On the other hand, a shark scientist sometimes does boring desk work, such as writing reports. Also, shark scientists don’t usually get paid a lot.

What qualities (品质) do you need to become a shark scientist?

Shark scientists need to be wise and strong. They enjoy working outdoors and they have to be cool and patient (耐心). They also have to be quite brave!

So do you think it’s a dangerous job?

Well, sharks have up to 15 rows of sharp teeth. However, sharks hardly attack (攻击) humans. There are over 350 kinds of sharks in the world and only about 10 are dangerous to us. In fact, dogs kill more people every year than sharks! Humans kill over 12 million sharks a year for food and sport!

How do you become a shark scientist?

A shark scientist usually studies Marine Science or Zoology at university. It’s also good to get some work experience in an aquarium (水族馆). In my opinion, I have the best job in the world!

小题1:_______ questions were asked about Daniel’s unusual job.

A.One

B.Two

C.Three

D.Four小题2:As a shark scientist, Daniel _______.

A.studies sharks in his neighbourhood

B.makes lots of money

C.swims with sharks for a living

D.only writes reports on sharks小题3:In Daniel’s opinion, one needs to be _______ to become a shark scientist.

①excited   ②patient      ③brave    ④strong   ⑤wise

A.①②③④

B.①③④⑤

C.②③④⑤

D.①②④⑤小题4:The underlined “Marine Science” and “Zoology” must be two _______ at university.

A.subjects

B.books

C.scientists

D.prizes小题5:From the passage we can know that _______.

A.sharks are likely to attack humans

B.dogs are as dangerous as sharks to humans

C.sharks are not dangerous to humans at all

D.humans do more harm to sharks than sharks do to humans

填空题