单项选择题
Someone is ringing the doorbell.Goand see().
A.who is heB.who he isC.who is itD.who it is
单项选择题 A left-luggage office is a place where bags()be left for a short time,especially at a railway station.
单项选择题 After two years' research, we now have a()better understanding of the disease.
单项选择题 It’s based on the idea()all people are created equal,()is accepted by most people.