I've had a cookie，but you'd better give

The boy promised ______late for school again.

A．to not be

B．not to be

C．not being

D．being not

用N_A表示阿伏加德罗常数的值．下列叙述正确的是（　　）

A．3.6g碳与3.36LO₂一定条件下恰好完全反应，生成CO分子数一定为0.3N_A

B．6.9g钠与足量的CO₂和H₂O（g）混合气体充分反应，转移的电子数一定为0.3N_A

C．25℃时，0.15mol/L的Na₂CO₃溶液中，Na⁺数目为0.3N_A

D．标准状况下，2.24L氯仿中含有C-Cl数目为0.3N_A

农业生态系统的结构越复杂越好吗？为什么？

Great attention must ______ education, especially in the countryside.

A．pay to develop

B．be paid to develop

C．pay to developing

D．be paid to developing