Because of Project Hope ,_____children h

阅读下面短文，根据短文内容完成下列句子。

     Schools all around the world have their own rules for students. However, perhaps one rule is

common in all lhe schools-students can't chew bubblegum in school.

    But every year on the first Friday in February, many schools in the USA encourage their students to

 "break the rule".  They hope the students can take part in the activity called Bubble Cum Day". The iclea

 of' Bubble Gum Day came from children's book writer Ruth Spiro. He thought it woulcl be cool to have

 lots of children chewing bubble gum and raising money on the same day. The money is often going to

 some charity. Bubble Gum Day turned out to be a sweet success.

    Now Bubble Gum Day is more and more popular in the country. Many people outside school also

 begin to join in the activity. Isn't it great?

1. All sclloo in all over the world have their _____ for students.

2. Bubble Gurn Day is on the first _____ in February in America.

3. _____ got the idea of Bubble Gum Day.

4.  Now Bubble Gum Day becomes very _____ in the USA.

5. Many people _____ begin to join in the activity.

某化工厂建于2002年，其锅炉污染应执行《大气污染物综合排放标准》(GB16297—1996)中二级标准，烟囱高度为60m，颗粒物的最高允许排放浓度是( )mg/m³，最高允许排放速率是( )kg/h。

A．120 85
B．150 150
C．150 100
D．100 80

北京市西城区统计局在业务上以（）的领导为主

A.北京市政府

B.北京市西城区政府

C.北京市统计局

D.国家统计局

食品安全法对进口预包装食品应当按照规定印制中文标签、中文说明书是如何规定的？

回差（迟滞）hysteresis