冬天，一直被冰冻着的衣服也会变干，这说明冰由________态直接变为________态了．
固；气
- I have heard you're going to change your job. Are you serious?
-- ______. I will quit my job.
A．Yes, I've made up my mind
B．No, I was just jokin
C．Yes, I do hope so
D．No, I' m not
什么是运算放大器的“虚地”？
