So convenient _______ to pay by credit card that more and more people apply for their credit cards.
| A．do people find | B．people find it | C．find people | D．do people find it |
—What was it that caused the party to be put off?
—________ the invitations.
| A．Because Tom delayed sending |
| B．Tom delayed to send |
| C．That Tom delayed sending |
| D．Tom delayed sending |
Who ________ that played a trick on the new English teacher?
| A．it was |
| B．was it |
| C．he was |
| D．was him |
—Where did you pick up the stamp?
—It was at the post office ________ we worked in the summer vacation.
| A．that |
| B．where |
| C．which |
| D．when |
—Was it by cutting down staff ________ she saved the firm?
—No，it was by improving work efficiency.
| A．when |
| B．what |
| C．how |
| D．that |
Is it that you often play computer games ________ worries your parents?
| A．why |
| B．that |
| C．which |
| D．what |