下列有关发热概念的叙述哪项是正确的A．体温超过正常值0.5℃ B．产热过程超过散热过

阅读理解。

     Here is a photo of Mr White's family. The man in the photo is Mr White, the father. The woman is the

mother. They have (有) two sons. The boy behind (在……后面) Mr White is Dave. He is ten. The boy

behind Mrs White is Paul. He is eleven. Dave and Paul are in the same school (同一所学校), but not the

same grade (年级). Dave is in Grade Five, Paul is in Grade Six. They are good students.

1. There are (有) _____ people in the photo.[ ]

A. five

B. there

C. four

D. six

2. Paul is behind _____. [ ]

A. Dave

B. Paul

C. Mr White

D. Mrs White

3. Mr and Mrs White have _____. [ ]

A. one boy and one girl

B. two boys

C. two girls

D. one boy

4. Dave is _____ brother. [ ]

A. Mr White's

B. Paul's

C. Dave's

D. Mrs White

5. How old are Paul and Dave? [ ]

A. Ten and eleven.

B. Eleven and ten.

C. Eleven.

D. Ten.

客运专线铁路将环境保护内容引入到路基工程中要求路基施工中必须做好环境保护的安排制定环境保护措施主要包括哪些方面

根据微观经济学的观点，一般均衡模型假定生产系数是可变的。

若一个热力系统和外界之间只有热量和机械等能量交换而无物质交换，这种系统称为（）

A.开口系统

B.闭口系统

C.绝热系统

D.孤立系统

中国下一代互联网示范工程最大的核心网是（）

A.GERNET2

B.Internet

C.LAN