my model plane is broken. i donot know_____ a.what to do b.how to do
问题描述：
my model plane is broken. i donot know_____ a.what to do b.how to do
答
my model plane is broken.i donot know_____ a.what to do b.how to do
答案：A
what to do 做某事,how to do it 怎样做