What the scientist said sounded strange, ______, they made sense [ ]

You must have missed the last train to Guangzhou the other day.- Oh, no, I _____.

you finished your composition already, Jack― Yes I _____ it within half an hour

Have you heard the good _______—Yes! The radio says China will send anexplorer(探险家）toMars.

Do you often go to school ____ bike—No, I often go there ____ foot.