I found the lecture hard to follow because it _______ when I arrived

The old man,_______ abroad for 20 years, ison the way back to his mother land.

Zhang Guorong’s singing career _________ about over 20years. It was his ________ appearance at singing in public.

Tom, your homework all the time. It’ not good for your eyes.

Einstein liked Bose’s paper so much that he________his own work and translated into German.