My mobile phone dropped into the water when I was walking along the river bank.—________！

It was not _____ she took off dark glasses _____ I realized she was a famous film star.[ ]

May Igo to the concert with you — I’mafraid not ______ you have a ticket, because I have only one.

Studies show that people are more_________tosuffer from back problems if they always sit before computer screens for longhours.

You don’t __ to go there if you have no time.