There is no doubt that all this puts a large _________ on a teacher with a large number of classes.
| A．tax | B．catastrophe | C．sense | D．burden |
Not only ______ polluted but ______ crowded.
| A．was the city; were the streets | B．the city was; were the streets |
| C．was the city; the streets were | D．the city was; the streets were |
The book I bought from the bookstore isn’t here. Who __________?
| A．could have taken it | B．must have taken it |
| C．might take it | D．should take it. |
The official made the demand that the soldiers _____ at once ______ battlefront.
| A．leave; for | B．leave; to | C．left; to | D．to be left; for |
— I will come to attend your lecture at 10:00 tomorrow.
— I’m sorry, by then my lecture will have ended and I _____ in my office.
| A．is being worked | B．will work | C．will be working | D．will have worked |
TheInternetin modern society hasbrought_______greatchangesinour daily life.
| A．about | B．out | C．back | D．up |