Mary didn’t know who ________ the problem she met with at that time.

Would you like _______bread No, thank you. I don’t want to eat ______ at the moment.

Many fantastic photos __________ during my last visit to Beijing.

Most birds find it safe to sleep in the trees, but they have eggs or young chicks, they don’t use a nest.[ ]

He ______busy yesterday,or he______you with your experiment