Mike had just finished his lunch and was about to take a break _____ an unexpected visitor came

Online music providers in China hope to set up a planthat will charge individual users for music

Her parents’ quarreling with each other ____________led to her family’s breaking up.

If he ________harder , he will catch up with us soon .

rains leave every 15 minutes; if you miss ____ , you don’t have to wait long for another.