下列对甲烷和乙烯的描述正确的是

A．乙烯比甲烷的碳的质量分数低

B．燃烧时，乙烯与甲烷现象一样

C．它们都能使溴水褪色

D．充分燃烧时，产物都是二氧化碳和水

China Daily is _______ a paper. It helps to improve our English.

A．more than

B．no more than

C．not more than

D．no more