I hesitated for a moment before choosing, otherwise, I the mistake.[ ]

Mary didn’t know who _________ the problem she met with at that time. But now her true friend Betty is always with her.

________ the alien was in the museum, Icalled the TV station.

For many years we have been keepingin ____by sending each other e-mails or phone calls

We _________ in Nanchang ever since we came to China.