问题 解答题

有一杯糖水,重b克,其中含糖a克,现在向糖水中再加m克糖,此时糖水变得更甜了,(其中a,b,m∈

R+)。

(1)请从上面事例中提炼出一个不等式;(要求:①使用题目中字母;②标明字母应满足条件)

(2)利用你学过的证明方法对提炼出的不等式进行证明。

答案

(1)解:

(2)证明:用综合法证明:

因为b>a,所以a-b<0,所以

因此,

阅读理解

阅读理解

     After decades of skimpy(小而暴露的)skirts and sleeveless tops on game days, some schools in the

US are saying cheerleader uniforms will have to meet stricter dress codes when they are worn in class.

     In Lake County, Florida, cheerleaders with uniforms too skimpy for the code are being asked to wear

long shorts or trousers under their skirts and a T-shirt under the sleeveless tops , according to a district

memo. Principals at two of Lake's eight high schools-Leesburg and Lake Minneola-are not allowing the

outfits in school at all.

     Michelle Thomas, a cheerleader at Leesburg High School, was disappointed when she learned she

couldn't wear her outfit to school on game days.

     "It shows that we're a team just like all the other sports." She said.

     But the school administrators didn't agree. "During the educational portion of the day, they have to

meet the dress code just like every other student," said school board chairwoman Debbie Stivender,

who ordered the staff to bring the outfits into line with the dress code.

     Bare midriffs(露腰装) are banned across the state by the Florida High School Athletic Association,

but no state rules mention cheerleader miniskirts. Sheila Noone, a spokeswoman for cheerleading

uniform company Varsity Brands, says the outfits haven't become more revealing over the last 10 years.

She says that the short skirts are designed to help the girls jump and kick.

     "Cheerleading is athletic," Noone said. "There's a lot of jumping so you won't want a knee-length skirt

that might hamper a toe touch."

     Most cheerleaders were sad to hear the news, but say they'll follow the rules. Even male cheerleaders, whose pants and tops meet dress codes, chose not to wear their outfits to show unity.

     "I understand, because they are kind of short," said Holly Bishop,14, a Lake Minneola High School

cheerleader, about her miniskirt. "It would've been really, really cool to wear them to school."

1. According to the new dress codes for cheerleaders in some American schools,_________.

A. bare midriffs are banned

B. cheerleading miniskirts are banned

C. cheerleader uniforms have switched from skirts to trousers

D. cheerleaders have to make their uniforms less revealing.

2. Which of the following statements is TRUE according to the article?

A. School administrators believe cheerleader uniforms do not match school dress codes.

B. Most cheerleaders show understanding of the new dress codes.

C. Sheila Noone believes that cheerleading miniskirts are not revealing.

D. School administrators don't take cheerleading seriously.

3.Some cheerleaders are not happy about the news because_______.

A. they hate the dress codes that other sports have  

B. they consider their uniforms special and cool

C. they want to wear revealing clothes

D. they will have to buy new uniforms

4. What is the main point of the article?

A. Stricter dress codes for cheerleaders meet opposition.

B. Positive reactions to stricter dress codes for cheerleaders

C. American schools encourage unity in dress codes.

D. Changes in dress codes for cheerleaders in American high schools.

5. What does the underlined word "hamper" in paragraph 7 mean?

A. protect      

B. miss    

C. prevent    

D. help

单项选择题