题干

已知函数
x
2
+
a
x
+
b
x
2
+
x
-
2
,x>1
x+
1
3
,x≤1
在x=1处连续,则a+b=(  )

A:1

B:-1

C:5

D:-5

上一题 下一题 0.0难度 选择题 更新时间:2018-02-12 02:28:16

答案(点此获取答案解析)

B

同类题1

完形填空,根据短文内容,从各题所给的A、B、C、D四个选项中选出最佳选项。

    Kevin sat at the desk in his study, pencil in hand. He had to write a story for his English class by Friday. “I don't know what to1,” he complained to his dog, who was asleep at his feet. Kevin was talkative when speaking to his friends, yet he had2finding words he had to write.

    By bedtime Kevin had drawn a picture of his dog smiling. He had drawn a tree with its branches(树枝) blowing in a high wind. He had also written a3asking his friend to go to the movies on Saturday.4he had not written a single word of his story.

    On Wednesday, Mrs Scott, Kevin's English teacher, asked the class to5the first draft() of their stories. Kevin had to turn in the only work that he had—the page with his name, the6, and the note.

    Kevin wasn't7when Mrs Scott asked him to stay after class the next day. But he was surprised by what8said to him. “Kevin, this is a fantastic story—the dog, the movie, the tree in the9. I can't wait to find out how they all fit together. I think you have the idea of a story there. Look at your note and the pictures and try to see10a story comes to you.”

    That night Kevin sat at his desk, and this was what he wrote: “One Saturday Tom went to meet his friend at the11. It looked as if it might rain, so Tom12his umbrella. Suddenly a big storm blew in. The noise of the wind13like Tom's dog Spotty. Spotty really hated storms and barked whenever he wanted to be let inside. Then Tom saw Spotty running after him down the busy street, barking. The sound was full of blame(责备). Tom felt14because he had left Spotty outside. He turned and headed home with Spotty. Tom let Spotty in the door just and the rain started to pour down.”

    Kevin had a story after all. The last thing he did was to write his name15at the top of the page.

同类题5

配对阅读。请为每个人选择最适合阅读的书,并将答案的字母编号填写在括号内。

____ Kate wants to keep thinner and healthier.
____ Tom is collecting information about how to prevent electrical fire.
____ Betty is trying to advise her mother to do some sports.
____ Sophia has to know some ways to prevent common cold.
____ Jane is studying health insurance(保险).
A.This book will help you understand how to stay well and avoid disease. You’ll learn some things that you might use at home to be away from cold.
B.Do you want to know how much food you should eat every day? Do you want to make a good plan about your meals? If so, please read this book. From the book, you will know about safe ways to lose weight and how many calories you need each day.
C.Do you have difficulties to communicate with others? Do you often say something wrong when you talk to others? This book will teach you how to say proper things to different people in different places.
D.This book will tell you something about how to keep healthy by taking exercise, but also the ways of taking exercise.
E. Are you worried parents? Do you have trouble in teaching your children? This book is written by a famous psychologist. It can help you understand your children well and make friends with them.
F. You will know why people need health insurance by reading this book. You can also know how to choose health insurance and how to use insurance to pay for your health in this book.
G. You will get useful information about how to prevent common accidents from this book. It’s about safety both indoors and outdoors.