—Was it there ______ you were away to see your friend off?—I’m not sure.But when I got back, it was gone.
Only when I left my parents for Italy ___ how much I loved them.
It was not until 1920 ___ regular radio broadcasts began.
The reason _____ he explained is ___ she was ill.
_______, the disease diphtheria would produce a powerful poison that would kill the paient.
He ___ in Nanjing where he ____ by his aunt.