The person in front of me at ＿＿＿checkout was using ＿＿＿card to check out butfound it wasn't working.
| A．不填；a | B．the; a | C．a; the | D．the; the |
Most environmental problems exist because adequate measures for preventing them ____in the past.
| A．not being taken | B．didn’t take |
| C．were not taken | D．haven’t taken |
—Go for a picnic this weekend, OK?
—__________. I love getting close to nature.
| A．I couldn’t agree more | B．I’m afraid not |
| C．I believe not | D．I don’t think so |
__________ Tom didn’t pass the exam made his parents very upset.
| A．Which | B．What | C．That | D．When |
She is not certain about __________ she has done anything wrong.
| A．if | B．whether | C．that | D．What |
People started to dig in the area for treasure, __________ much damage.
| A．causing | B．to cause |
| C．has caused | D．Cause |