A:500mL 10mL
B:250mL 5mL
C:100mL 2mL
D:50mL 2mL
下列行为符合男女同学正常交往原则的是 ( )
— We can invite Nick and Nora to Shanghai Disneyland with us.
— _________? I'll give them a call right now.
以下是小明同学对一些工具及其原理的总结,其中说法正确的是( )