﹣﹣﹣Shall we go out and do some outdoor activities？
﹣﹣﹣_______.（ ）
A．You're welcome
B．That's a good idea
C．Don't worry
D．It's none of your business
Paper is ________ useful invention.It was invented around 2，000 years ago by Cai Lun.（ ）
A．aB．anC．/D．the
﹣﹣Shall we go for a walk？
﹣﹣_____________.It's too dark.We'd better stay at home.（ ）
A．Nice ideaB．That's true
C．Don't be sillyD．I agree with you
﹣﹣Could you tell me ______________ "the Father of Rice "？
﹣﹣Because he helped many countries grow more rice.（ ）
A．when was Yuan Longping called
B．why is Yuan Longping called
C．when Yuan Longping was called
D．why Yuan Longping is called
My cousin became a country doctor ____________ he finished medical school.（ ）
A．afterB．so thatC．butD．so