Mum, it is nice weather. I want to skate this afternoon. —Don’t you think the ice on the lake is too thin to ________ your weight.

Where is Class________ ?It’s on the ______ floor.

Mrs. Green takes the _______that children should be allowed to learn at their own speed.

It’s a pity that you ______ leave so soon. Your uncle will be home in 10 minutes and he misses you so much.

s Beidou global satellite navigation system willhave been completed by 2020, ________ of more than 30 satellites