问题
选择题
I like getting up very early in summer. The morning air is so good ____.
A．to be breathed
B．to breathe
C．breathing
D．being breathed
答案
答案：B
有一些形容词后与不定式连用，主动表被动。此类形容词有：easy, hard,difficult,heavy,good,pleasant等等。故选B。