将拥有二十四个记忆单位的二十四个节气编码成只有四大记忆单位的《二十四节气歌》帮助记忆,这是利用了记忆编码中的()策略。
A.系统化
B.联想
C.替换
D.组块
参考答案:D
氢气的摩尔质量为M g·mol-1,密度是ρ g·L-1,阿伏加德罗常数为NA,则下列表述正确的是
A.单位体积中所含氢气分子数目NA/22.4
B.单位质量中所含氢气分子数目为ρ·NA
C.单个氢气分子的质量为M/NA g
D.单个氢气分子占有的体积为22.4/NA L
—I'll tell something about the change in your job tomorrow.
—You ________ me some time earlier.
A.ought to tell
B.would have told
C.must tell
D.should have told