问题 选择题
在直线y=x到A(1,-1)距离最短的点是(  )
A.(0,0)B.(1,1)C.(-1,-1)D.(
1
2
,-
1
2
答案

由直线y=x,得到斜率k=1,

则与y=x垂直的直线斜率k′=-1,又P(1,-1),

所以过P且与y=x垂直的直线方程为:y+1=-1(x-1),即y=-x,

联立得:

y=x
y=-x
,解得:
x=0
y=0

则直线y=x到A(1,-1)距离最短的点是(0,0).

故选A

阅读理解

When Daniel woke up yesterday morning, he found he was a bit late for school, so he started running to catch the bus. Moments later, he saw a dog, but not its lead. He tripped over the lead and fell down. He jumped up quickly, went on running and got on the bus. After a while an old coach broke down in the middle of the road, and the driver couldn’t move it. It was eight o’clock, the middle of the rush hour, so it soon created a terrible traffic jam. The bus driver tried to go round the coach. Unfortunately a taxi was coming in the opposite direction. The driver tried to stop the taxi, but he couldn’t prevent the accident— the taxi crashed into the front of the bus! Luckily nobody was hurt.

When Daniel finally got to school out of breath, the Science lesson had been on for five minutes. Daniel said sorry to the teacher and sat at his desk. He reached out for his school bag— no, it was nowhere to be found.

“Where is my school bag?” Daniel was puzzled. Suddenly he realized that he had left it on the bus. Bad luck!

小题1:What does the underlined word “tripped” mean?

A.扔掉

B.拣起

C.绊,绊倒

D.跨越小题2:What is the order of the accident?

①A taxi was coming in the opposite direction

②The bus driver went round the coach.

③An old coach broke down.

④The taxi crashed into the bus.

A.①→④→②→③

B. ②→③→①→④

C.③→②→④→①

D.③→②→①→④小题3:What is the best title for this passage?

A.An unlucky day

B.A happy day out

C.A traffic accident

D.A strict teacher

问答题