A：100毫升的溶液中含有Mg2+、Cl-—总数为0.3NA
B：100毫升的溶液中含有Mg2+数目是0.1NA
C：1升溶液中Mg2+的浓度是0.3mol / L
D：1.5升溶液中含有Cl-的浓度是4.5mol / L
一质量为1kg的质点静止于光滑水平面上，从t=0时起，第1秒内受到2N的水平外力作用，第2秒内受到同方向的1N的外力作用。下列判断正确的是( )
(____) No, I don't like winter.
(____) Which season do you like best, Lily?
(____) Winter. I can play with snow.
(____) So I like autumn best. It's always sunny and cool.
(____) What about you? Do you like winter, too?
(____) It's too cold.
