Could you tell me ______ it takes to go from here to Beijing by air? —About 50 minutes.[ ]

Therea lot ofat this time last year.

Beijing has got_____ population of more than 13.8 million.

Polly’s mother was anxious about ______ she could get home safely in ______ foggy a day.

There is no doubt _____ she will be able to repay the money on time.