对于加油站而言，满意的客户未必留下来，而留下来的客户未必是满意的客户，通常有哪几种情

下列各对数中，互为相反数的是（　　）

A．-|-5|和+（-5）

B．+（-6）和-（+6）

C．（-2）³和-2³

D．（-3）²和-3²

阅读理解。

Dear Peter,

     My name is Frank．I am from(来自)America．Here is a picture of my class(班)．We are in Class

One, Grade Seven．

     You can see my friends in the picture．Jimmy likes to play basketball．He likes to eat apples and

French fries．Helen likes math．Her favourite food is hamburgers．Sandra doesn't like math．But

shecan speak French(法语)．She likes ping-pong．Sally is a black(黑人的) girl．She likes to swim

(游泳)．She likes to eat ice cream．I like math too．Can you find(寻找) me? I like to eat bananas．

Maria likes computer very much．She plays computer games very well．Nick is fun．He can play

football．He likes strawberries best．

     Can you send(发送)me a picture of your class?

                                                                                                                                           Yours,

                                                                                                                                            Frank

1．Frank has    __    friends．

A．seven

B．six

C．five

2．___     like sports．

A．Jimmy, Sandra and Sally

B．Maria, Nick and Jimmy  

C．Sally, Nick, Jimmy and Sandra

3．    ___ and  ___    like math． 

A．Helen; Frank  

B．Sandra; Peter  

C．Helen; Sandra

4．    ___ and  ___    like fruit． 

A．Nick, Maria; Jimmy  

B．Nick, Frank; Peter  

C．Jimmy, Nick; Frank

5． ___    is the e-friend of Frank．

A．Sally

B．Sandra

C．Peter

工业革命中，在动力的发明和使用上，具有开创意义的成就是[ ]

A、蒸汽机车的发明

B、水力织布机的研制

C、改良蒸汽机的制成

D、水力纺织机的问世

党的十八大报告提出，要以（）引领创新型国家的建设。

A、技术交流

B、人才培养

C、思想创新

D、科技创新

离心泵发生汽蚀时，在叶轮中心附近会产生大量气泡，这些气泡里的气体是（）。

A.主要是空气

B.是空气和被输送液体蒸汽的混合物

C.主要是被输送液体的蒸汽

D.不好说