题干
There were no women in the committee 1976, but now women are in a majority.
A：before to
B：previous to
C：ago
D：earlier
答案(点此获取答案解析）
B
伏加德罗常数是NA(/mol)，铜的
摩尔质量是μ(K
g/mol)，铜的密度是ρ（Kg/m3），则下述结论中正确的是（ ）