.According to some doctors, one of the ways to prevent us from growing old is to make sure that our brains get enough___.
No one knows __________ it will be fine tomorrow and __________ we can play basketball together.
Loulan is believed __________ over by sandstorms gradually from AD200 to AD400.
They were having an argument about __________ turn it was to do the cooking.
His son has __________ the running of his company, including six London theatres.
The new road is __________ of the old one.