有三个红色圆珠可能是红宝石、玻璃、尖晶石、石榴石、碧玺，如何区分？

阅读理解。

     While most high school students spend most of their time worrying about who likes who,and

different re lationships between their classmates,I choose to focus on my school lessons and sports.

     When I was young,my mother encouraged me to develop and keep friendship with boys in

order to build strong relationships. But she told me not to risk a good friendship with a boy with

the title of boyfriend. It's indeed a wise choice to stay friends with those of the opposite sex. In my

opinion, even though some high school relationships might continue after graduation,the probability

of them lasting much longer is so slim that there really is not a point to it.

     Firstly you have to think about such a question－whether it is possible to hurt both of you,or

even hurt both of your future husbands or wives. My second point is that you still can date if you

hope marriage could possibly follow. Except this,there really is not any other reason for dating.

Some students desire relationships for a chance to be romantic. While these are nice to have,there

are many more important things at this point in our lives.

     The titles of boyfriend and girlfriend put too much stress on a relationship between high school

students. Just staying as common friends may be the best choice for us. I strongly recommend we

should deal with it in an appropriate way and follow our teachers' advice if necessary.

1．The author writes this passage probably for ________ to read.

A．high school students  

B．school teachers

C．parents and teachers  

D．married couples

2．Between sexes,the relationship of being good friends might be ________ than that of being

boy/girlfriends.

A．weaker  

B．safer

C．slimmer  

D．stronger

3．How does the writer like the idea of dating among the students?

A．Dating is a nice chance for students to be romantic.

B．Studying is far more important than dating in school.

C．In high school dating can surely lead to future marriage.

D．Dating in high school is sure to hurt your future family.

4．The underlined word "it" in the last paragraph might refer to________.

A．the title of boyfriend or girlfriend at school

B．advice given by both teachers and parents

C．the pressure from school lessons and sports

D．the relationship between students of opposite sexes

产生X线对比度最好的系统是

A．消化系统

B．泌尿系统

C．生殖系统

D．呼吸系统

E．循环系统

某使用国有资金的建设项目，在招标过程中，发生了以下事件。
事件1：共有A、B、C、D、E 5家投标人购买了标书，并在投标截止时间之前递交了投标文件。
(1)在开标前15 min，D投标人要求撤回投标文件，招标人不予同意。在D投标人的强烈要求下，招标人同意其撤回投标文件，但声明D投标人的投标保证金将被没收。
(2)投标截止时，E投标人仍未按照招标文件要求缴纳投标保证金，但作出了缴纳投标保证金的书面承诺。
事件2：评标委员会在开标后的初步评审中发现，投标人B和C的投标文件满足招标文件的要求；投标人A提出的货物检验方法不满足招标文件的要求。在随后的详细评审中，评标委员会要求B、C两个投标人对其如何解决技术难点问题提出具体措施，并适当降低报价。
事件3：评标委员会按招标文件确定的评分标准，推荐B投标人为第一中标候选人。招标人在投标有效期结束日30个工作日前的8月22日发出了中标通知书，并于9月25日与B投标人正式签订了合同。
问 题：

事件2中，评标委员会应做出怎样的初步评审意见详细评审中的做法是否妥当说明理由。

试述如何进行爆震传感器的检测？

在导线可共管敷设中，可穿人同一根导管内的回路有（）。

A.50V及以下的2个回路

B.同一设备的3个电机回路

C.无干扰的2个控制回路

D.照明花灯的3个回路

E.同类照明的8个回路