I haven’t seen you for a couple of daysWhat have you been up _____?

Is the physics problem _________—- Yes, I can work it out _________.

Moyan has won the Noble Prize in Literature, which has made him world-famous, but before that no one could have imagined how great a role he _______ in the literary world

I’m sure our surroundings will become better. — It is still a problem _____ we can control the pollution. [ ]

Not only I but also Jane ______having one exam after another.