Historically, ________ main material for making tables has been wood, but ________ metal and stone have also been used.
E-mail, as well as telephones, ____________ an important part in daily communication.
You should pay more in Beijing if you want to rent an apartment ___________ south.
About 110 million people moved to this city. The population is ____________ as ten years ago.
— How do you find this film, John? —_____________.
I graduated from college twenty years ago and I ____________ as an English teacher in this middle school ever since.