---Make sure that you will come here on time.   --_______.

A．Certainly, I will

B．Don't worry.

C．That's OK.

D．Of course ,I can

N_A表示阿伏加德罗常数，下列叙述正确的是

A．等物质的量的N₂和CO所含分子数均为N_A

B．1.7g H₂O₂中含有的电子数为0.9 N_A

C．1mol Na₂O₂固体中含离子总数为4 N_A

D．标准状况下，2.24L甲烷所含共价键数为0.1 N_A