The twins have studied in this school .
Twenty foreign students visited our school yesterday.(改为一般疑问句)
twenty foreign students our school yesterday?
He hardly watches TV.(变成反意疑问句)
He hardly watches TV, ?
People drink Chinese tea all over the world.(改为被动语态)
Chinese tea all over the world.
My sister isn't old enough to dress herself.(改为同义句)
My sister is young she can't dress herself.
It 's half past eight.(对划线部分提问)
is it?