问题 多项选择题

关于杆件稳定基本概念的表述中,正确的是()。

A.如果受压杆件比较细长,则受压杆件要有安全的要求

B.压杆的截面大不易失稳,因为惯性矩大

C.压杆的长度大,临界应力小,不易失稳

D.当杆件长细比过大时,常常会发生失稳的破坏

E.长细比是影响临界应力的综合因素

答案

参考答案:B, D

阅读理解

阅读理解。

Dear Linda

    Thank you for your letter and photos. Do you want to know about my new school in America?

OK. I'll tell you. Our new school is not big. There are twenty-six classrooms in it. Our classroom is

very small. You can see fifteen students in it. Three of the girls come from Japan.Five of the girls are

English. Seven boys are Americans. My new English teacher is English.His name is Peter Green. He

is good with us. He likes animals. On weekends he often takes us to the zoo near our school. I have

a new friend here. Her name is Helen. She is not in my class.She is in Class Seven, Grade Eight. Oh,

my brother Mike is in her class. Helen is good at singing. She tells me she wants to be a musician.

Helen is an American girl. Her home is across from our school. After school I often have dinner at her

home. Her parents like me very much. OK. Please write and tell me about your new school in Canada.

1. _______ is in Canada.

A. Alice

B. Mike

C. Helen

D. Linda

2. There are _______ students in Alice's class.

A. five

B. seven

C. fifteen

D. twenty-six

3. Peter Green is _______.

A. English

B. American

C. Chinese

D. Japanese

4. Helen wants to be _______.

A. a teacher

B. a worker

C. a musician

D. a doctor

5. Which of the following sentences is right?     

A. Alice's classroom is big.     

B. Helen and Alice are in the same class.      

C. Mike is Linda's friend.      

D. Helen's home is across from Alice's school.

选择题