In the experiment we kept a watchful eye ________ the developments and recorded every detail.
| A．in | B．at |
| C．for | D．on |
I really ought to go on a diet。I ________ on so much weight since I gave up jogging.
| A．put | B．am putting | C．have put | D．had put |
I don’t understand how you got a ticket. I always ________ you ________ a careful driver.
| A．think; are | B．am thinking; are | C．thought; were | D．think; were |
—Did you enjoy your holiday?
—Yes, it’s the best holiday I ________ these years.
| A．had | B．have had | C．had had | D．would have |
—Look! Someone has spilt coffee on the carpet.
—Well, it ________ me.
| A．isn’t | B．hasn’t been | C．hadn’t been | D．wasn’t |
—I bought this shirt for 35 yuan yesterday.
—It’s on sale today for only 29. You should have waited.
—Oh, really? But how ________ I know?
| A．would | B．can | C．did | D．do |