发病率、患病率和病程三者的正确关系是（） A.发病率=患病率×病程 B.患病率=发病

驾驶机动车上路前应当检查车辆安全技术性能。

Do you know David? He is an American boy. He’s eleven. He is in Class Two, Grade One. He has a sister. Her name is Joy. She is five. They have a dog(狗). Its name is Dongdong. How old is it? I know it’s two.

小题1:David is a_______.

A． boy

B．girl

C．English boy

D．English girl小题2:David is__________ and Joy is____________

A．five; five

B．eleven; four

C．five; eleven

D．eleven; five小题3:Joy is David’s_________.

A． brother

B．friend

C．sister

D．classmate小题4:Dongdong is the name of a___________.

A．cat

B． dog

C．bird

D．child小题5:The dog is________.

A．eleven

B．five

C．two

D．one

下列物质中属于非电解质的是（　　）

A．氯化钾的水溶液

B．液态氯化氢

C．气态甲烷

D．作电极的碳棒

—Which one of these T—shirts do you want?  —______，Either will be OK.

A．No problem

B．I’m sure

C．Thanks

D．I don’t mind

饲料、饲料添加剂生产企业委托其他饲料、饲料添加剂企业生产的，委托方和受托方对委托生产的饲料、饲料添加剂质量安全承担连带责任。