Upon ______the classroom， I started thinking about my mother.
| A．leave | B．leaving |
| C．left | D．to leave |
I have an appointment ________ Dr Smith, but I need to change it.
| A．to |
| B．off |
| C．with |
| D．from |
—Would you mind answering some questions on shopping habits?
—_______.
| A．Yes, with great pleasure |
| B．No, I am afraid I can’t make it. |
| C．Yes, it is worth the time. |
| D．No, as long as it doesn’t take long. |
Marco Polo is said to have sailed on ________ Pacific Ocean on his way to Java in ________ thirteenth century.
| A．the; a |
| B．a; / |
| C．/; the |
| D．The; the |
Do not let any any failures discourage you, for you can never tell ________ close you may be to victory.
| A．how |
| B．that |
| C．which |
| D．where |
Experts believe ________ people can waste less food by shopping only when it is necessary.
| A．why |
| B．where |
| C．that |
| D．what |