向0.4L2.5mol/L的NaNO3溶液中加入()5mol/LNaNO3溶液可使其摩尔浓度达到4.5mol/L。
A.2L
B.2.4L
C.3L
D.1.6L
参考答案:D
— Don't drop paper on the ground.
— _____. [ ]
A. It doesn't matter
B. I am happy
C. I'd love to
D. OK
技术训练常用的方法有单个练习、班集体练习和中队集体练习。()