The rivers will become dirtier and dirtier ______ we take action to protect them.
| A．since | B．if | C．until | D．unless |
While you are having an exam, you must write as ________ as you can.
| A．careful | B．carefully | C．more carefully | D．most careful |
----Where’s your brother?
----He _______ to Beijing for the training.
| A．is going | B．has gone | C．will go | D．went |
The bus hasn’t come yet. Many people are waiting ______ the bus stop.
| A．at | B．for | C．on | D．in |
Today, there are still 40 _______ children needing help for education.
| A．million | B．millions | C．million of | D．millions of |
----________ there any food for the drivers and passengers?
----Yes, __________.
| A．Are; there are | B．Is; it is | C．Are; they are | D．Is; there is |