问题 填空题

已知点P是直线l上的一点,将直线l绕点P逆时针方向旋转角α(0°<α<90°),所得直线方程是x-y-2=0,若将它继续旋转90°-α角,所得直线方程是2x+y-1=0,则直线l的方程是______.

答案

由已知易得:

直线l经过直线x-y-2=0和2x+y-1=0的交点(1,-1),

且又与直线2x+y-1=0垂直,

∴l的方程为y+1=

1
2
(x-1),

即x-2y-3=0.

阅读理解

阅读理解。

     "I look at the beauty of the clothes firstly and then style and fit come second. Price is never really

something that I consider,”  says Augustine Masilela, a owner of a kids' clothing shop.    

     For Masilela, there is no limit (限制) to the amount she will take on children's clothes.    

     If she thinks the quality and style are great, she will take it. 

     Sonia Motaung does not mind throwing a few fashionable numbers into her seven-year-old kid's

wardrobe(衣柜).      

     "I believe a child should keep a child. She must still be able to play but not look careless, " she

says.      

     Some parents say boys are difficult to shop for.     

      " To make my son look good , I dress him in designer labels (栎签) , "  says Kgomotso  

Mogotlane.     

     She says shopping for her three-year-old boy can be a null thing, but she has thought of lots of ways to make it fun.      

     While it is often a parent that decides on a child's wardrobe, some mothers let their kids choose.      

     "I go shopping with my four-year-old son and let him choose what he wants, " says Uyanda Mbuli.      

     Of course, when they reach a certain age, children start choosing their own coats.      

     "I like to go with my mother when she buys my clothes because then I can choose what I want, " says

Sipho Mdluli( 12) .      

     Whether it's the kids who choose what they want to be seen in or their parents who take the lead,

children are surely looking cool.

1. Masilela pays more attention to the clothes' ________ first when she wants to buy one.    

A. price    

B. beauty    

C. fit        

D. style

2. Who often goes shopping with her/his kid?    

A. Motaung.              

B. Mogotlane.    

C. Mbuli.                

D. Masilela.

3. The last paragraph shows kids want to wear ______ clothes.    

A. expensive            

B. comfortable

C. fashionable            

D. Cheap

多项选择题