在△ABC中,角A、B、C的对边边长分别是a、b、c,若A=π3,a=3,b=1

题型:填空题

问题:

在△ABC中,角A、B、C的对边边长分别是a、b、c,若A=
π
3
a=
3
,b=1,则c的值为______.
考点:解三角形
题型:填空题

地球上有170万个已被鉴定的物种。由于环境污染和环境破坏,大量物种灭绝。目前已经发展到每天消失一种,每小时消失一个野生动物种的程度,这种情况严重破坏了[     ]

A.人类健康状况

B.生态平衡

C.经济发展

D.社会发展

题型:填空题

     A few years I was on a bicycle trip when I got off my bike for a rest. I sat down on the grass. A few

seconds later, I was covered in ants. They were swarming all over me so I got up and brushed them off.

It was a strange experience but I soon forgot about it.

     A couple of years later, I was living in Jordan. I had just moved into a modern flat and was unpacking

plates when I saw something move out of the corner of my eye. I looked over at the kitchen drawer and

there was a cockroach(蟑螂) crawling out of it. I screamed. Then I grabbed a can of insecticide and

sprayed it on the cockroach. He ran under the nearby bathroom door. It took me three days before I

found the courage to open the bathroom door to see if he was still alive. He wasn't.

     Why did I react so violently to one lone insect when a closer encounter with hundreds of ants hardly

affected me? The answer is easy: because cockroaches are creepy crawlies(令人害怕的爬虫) and ants

aren't. Creepy crawlies are those little bugs which provoke feelings such as apprehension(忧虑), anxiety

or aversion(讨厌) - they make your skin crawl.

     Did you know that some people feel such a fear of bugs that it becomes a phobia(恐惧)?

Psychologists have offered many explanations. Some say we associate them with dirt and disease. Or

that these are life forms that are so alien to us, that we find them repulsive(排斥的) for their dissimilarity.

     Insects, however, don't follow our rules - they just do what they want and invade our space.

Unfortunately, although insects and bugs have been a successful animal species up to now, many of them,

like many other species nowadays, are under threat of extinction. Entomologists(昆虫学家) warn that

this could upset entire ecosystems and lead to all kinds of disastrous consequences. So my plea to you is:

the next time you feel the urge to stamp on, splatter or spray a creepy crawly, give a thought to the planet

and stop.

1. Why did the author mention the ants in the beginning?

A. Because the experience with the ants presents a sharp contrast to that with the cockroach later.

B. Because the author wants to show her preference to the ants and her dislike for the cockroach.

C. Because both ants and cockroaches are creepy crawlies that the author dislikes.

D. Because meeting the ants is an unusual experience that the author can hardly forget.                              

2. What does "insecticide" in the second paragraph probably mean?                            

A. A kind of fruit juice.

B. A kitchen knife.

C. Liquid for killing insects.

D. Cleanser for the bathroom.                                                                                                               

3. How does the author feel about the bugs like cockroaches?

A. The author doesn't mind the contact with those harmless small creatures.

B. They make the author feel so awful that they should be killed.

C. They invade our space and become a threat to humans.

D. They still deserve a place for keeping the balance of the nature.hundreds of ants.

4. Which of the following is NOT the reason why the cockroach makes the author's skin crawl?

A. It looks so strange and different that the author can't accept its appearance.

B. It can make the author feel sick and cause a strong dislike.

C. The author may relate it to something dirty or disease at the sight of it.

D. It reminds the author of the experience of meeting

5. Which of the following statements about bugs is NOT true according to the passage?

A. Some people may be frightened so much by bugs that it leads to a psychological barrier in some

degree.

B. People can enjoy a cleaner living environment if more bugs like cockroaches are killed.

C. Many bugs are in danger of extinction so they should be placed under human's protection.

D. Some bugs are extremely unpleasant that people have a strong wish to destroy them.

题型:填空题

公元4世纪,罗马帝国皇帝_______在欧亚两洲交界的要地营建帝国的新都——_________。公元____年,罗马皇帝__________临终时,将帝国分成东西两部分,至此,罗马帝国分裂为东西两个帝国。东罗马帝国因其首都旧名为_____________,故称“_______________”。

题型:填空题

某工程单代号搭接网络计划如下图所示,节点中下方数字为该工作的持续时间,其中的关键工作为()。

A.工作A、工作C和工作E

B.工作B、工作D和工作F

C.工作C、工作E和工作F

D.工作B、工作E和工作F

题型:填空题

某企业于2008年从境外分回投资所得70万元,境外适用税率为30%,其抵免限额为()。

A.17.5万

B.21万

C.25万

D.30万

更多题库