Though ___very nice,the smoke from a wood-burning fire can cause a lot of harm.
问题描述：
Though ___very nice,the smoke from a wood-burning fire can cause a lot of harm.
A smelling
B to smell
C smelt
D being smelt
答
选A
原来的句子应该是though the smoke smells very nice.
smell 是主动形式的 所以换成分词从句 用smelling