A:NH4Cl的电子式:
B:用电子式表示氯化氢分子的形成过程:
C:氧化钠的电子式:
D:R2+离子核外有a个电子,b个中子,R原子表示为: a+2a+b+2 R
如图所示,若入射光线与平面镜成30°夹角,则( )
化简-32的值是( )
六(1)班第一组同学的体重是45千克、50千克、45千克、51千克、47千克、45千克.这组数据的众数是____,中位数是____,平均数是____.
— Linda won first prize in the English speaking competition last week.
—Yes, she didn't let her teacher down.
A. Is the man your father? B. No, I don't.
C. What are you going to be one day? D. What does he do?
E. Who's the man? F. Where does he work?
G. Does your father work in a car factory?
A:Hello. ____
B:Yes, he is my father.
A:____
B:He is an engineer.
B:He works in a car company. He likesdrawing pictures.
A:Do you like drawing pictures?
B:____ I like singing.
B:I'm going to be a singer one day.