[单选题]
A mole of diatomic oxygen molecules and a mole of diatomicjzl .. 47-qtxznvmktf r9cwb0v 05 hw8 nidwx q (5e4vcva)px+x5trogen molecules at qxc+ xaxp d)v5e(4w5v STP have
A. the same average molecular speeds.
B. the same number of molecules.
C. the same diffusion rates.
D. all of the above
