_____ all the inventions have in common is ______ they have succeeded.
| A．What； what | B．That； what |
| C．What； that | D．That； that |
Harry Potter has made reading popular again, ______ is why parents and teachers like the book, too．
| A．that | B．who |
| C．which | D．what |
Some countries have banned smoking in public places ______ public health．
| A．improve | B．to improve |
| C．improving | D．improved |
Mr．Smith had to go to work by bus this morning as his car ______．
| A．would repair | B．was repairing |
| C．had been repaired | D．was being repaired |
Food and fruit are forbidden in the library, ______ you are allowed to have drinks and sweets with you．
| A．and | B．but | C．so | D．or |
Being ______ highly skilled reader is ______ key to becoming successful in the Information Age．
| A．a; 不填 | B．不填; a |
| C．the; a | D．a; the |