题干
You were supposed to ________ your words carefully now that you meant no offence.
A：swallow
B：break
C：keep
D：weigh
答案(点此获取答案解析）
D
You were supposed to ________ your words carefully now that you meant no offence.
A：swallow
B：break
C：keep
D：weigh
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（ ）
（
，
）的图象如下所示，则（ ）
