A:42-23=19(辆)
B:23+42=65(辆)
C:42-19=23(辆)
D:23+19=42(辆)
如图,用直尺和圆规画∠AOB的平分线OE,其理论依据是____
He's a fashion designer who's always swum against the stream;his work is very ________.