Most of all Chinese homes now have microwave ovens, partly __________ less time to spend preparing food.
| A．as a reason of | B．as a result of |
| C．because | D．as a fact that |
—Waiter!
—
—I can’t eat this. It’s too salty.
| A．Yes, sir? | B．What? |
| C．All right? | D．Pardon? |
Children’s brains can’t develop properly_______ they lack protein(蛋白质).
| A．when | B．since | C．because | D．unless |
This is the very toy car ________ which he came here the other day.
| A．by | B．in | C．for | D．on |
Spacecraft “Discovery” has failed in the course of launch.
----_______? They have been preparing for the test.
| A．How come | B．When | C．How | D．Why not |
I began to fish before memory began, _______ I know I have always fished.
| A．so far | B．so as far as | C．as far as | D．so |