下列化学用语表示正确的是

A．丙烯的结构简式为: CH₂=CHCH₃

B．次氯酸的电子式为:

C．聚乙烯的结构简式为：-CH₂-CH₂-

D．氯化钠的电子式为：

The poor boy is in danger. We should do all we _____ help him out.

A．can do

B．can to

C．can to do

D．can