问题 解答题

某商场销售一批名牌衬衫,平均每天可售出20件,每件盈利40元,为了扩大销量,增加盈利,尽量减少库存,商场决定采取适当的降价措施.经调查发现,每件衬衫每降价1元,商场平均每天可多售出2件,试用函数表示当商场降价x元后该商场每天的盈利额y元;若商场每天要盈利1200元,请你帮助商场算一算,每件衬衫应降价多少元?

答案

y=(20+2x)(40-x)=-2x2+60x+800

当y=1200时,-2x2+60x+800=1200,

解之得,x1=20,x2=10.

考虑尽量减少库存x=20(元).

所以每件衬衫应降价20元.

选择题
阅读理解

Our particular parenting style reflects our own way of “looking”. Here’s a great piece of writing reflecting parent’s particular ways on the parenting style that have become known humorously as helicopter parenting and submarine parenting.

Helicopter parents hover over their children, managing every aspect of their child’s life. On the contrary, submarine parents remain “hidden” coming to the surface when guidance is needed.

While helicopter parents may have the best intentions, in reality, they are raising children with few problem solving skills. Children with hovering parents never get the chance to face disappointment and build up their ability to recover from misfortune.

Think about your typical submarine. Submarines usually remain underwater. In case of a need for emergency surfacing, submarines can rise so quickly. They are driven partially out of the water. Submarine parents also remain out of sight, yet able to appear in the case of an emergency.

I admit I’m a submarine mom. My job as a parent is to have fun with my daughters while letting them explore and learn natural consequences.

My older daughter found herself acting in commercials and making more than minimum wage as a teen. To give her a sense of the real world, I insisted she spend three weeks every summer, picking strawberries and earning $3.50 on a good day.

When my youngest daughter Sondra was six, she wanted a very expensive American Girl Doll. I cut the full color 18" picture out of the American Girl catalogue and had it laminated (压膜). “Here’s your American Girl Doll.” I said “When you turn nine, I’ll buy you the 3D doll on your birthday.” Sondra played with her flat doll for months, making clothes and furniture for her. She learned creativity. I saved $88.00.

小题1:What is the text mainly about?

A.Various means of transportation.

B.Funny experiences of a mom.

C.Humorous stories about parents.

D.Different styles of parenting.小题2:The underlined phrase “hover over” in Paragraph 2 is closest in meaning to “_____”.

A.leave behind

B.fly around

C.watch over

D.set aside小题3:Which of the following can be learned about helicopter parents from the passage?

A.They give their children proper guidance.

B.They try to do everything for their children.

C.They teach their children how to face failures.

D.They help their children explore by themselves.小题4:The author supports her point of view mainly by _____.

A.stating facts and offering advice

B.using figures and giving evidence

C.analyzing data and drawing conclusions

D.making comparisons and giving examples