we are extremely sensitive to smell.

问题描述:

we are extremely sensitive to smell.
1.这里为什么不用have而用are
2.smell是做名词还是动词?to是否可省?

be sensitive to对.敏感,sensitive是形容词,have后面要加名词
smell是名词,味道,to不能省略,固定短语,后面加名词