When he was awake, she found she was lying on _______ seemed to be a piece of stone.
| A．that | B．which | C．what | D．it |
New traffic rules that took effect on January l, 2013 are much stricter______ than in the past．
| A．that | B．this | C．those | D．what |
Rock climbing is ___ great fun. You will get close to ____ nature and take adventures at the same time.
| A．/; / | B．a; / | C．a; the | D．/; the |
— In order to improve your English, you need to practice more.
— ______. Practice makes perfect.
| A．Certainly, go ahead | B．Well, it depends |
| C．I don’t think so. | D．I couldn’t agree more |
How the fire in the dancing hall started _________ a mystery.
| A．to remain | B．remains |
| C．is remaining | D．is remained |
Please don’t try to back out _____ everything has been arranged.
| A．until | B．though | C．when | D．unless |