英语His drawings air very good.中为什么drawings要加ing啊!还有问下good 和we

drawing是名词,‘画’的意思
这个句子的意思是他的画（风）干得很好.air是动词,‘干’的意思,air,vt.vi.
to become dry and/or fresh,or to cause to become dry and/or fresh:
My mother always airs the sheets before she makes the beds.
Leave the windows open to let the room air a bit.把窗子打开让房间干一点