So fast _____that it is difficult for us to imagine its speed.
| A．light travel | B．is light travel | C．does light travel | D．travels light |
After receiving the news , immediate _______ had been taken by the local government to stop the disease spreading .
| A．speed | B．behavior | C．action | D．measure |
As with ____ businessmen , most teachers have ____ very busy life nowadays .
| A．the ; 不填 | B．the ; a | C．不填；不填 | D．不填； a |
His coming adds to the difficulty we ____ the problem
| A．have to solve | B．have solve | C．have solved | D．have solving |
Books are the most important records we ______ man’s thought, ideas and feelings .
| A．keep up | B．keep of | C．keep down | D．keep on |
--- If the manager is free and _____ us, please tell him that we _______ .
| A．will receive ; waited | B．will receive ; have arrived |
| C．receives; have waited | D．receives; arrived |