E-mail is much _____ than long-distance calling.
| A．cheap | B．cheaper | C．cheapest | D．the cheapest |
This apple is_____ than that one.
| A．big | B．bigger | C．biggest | D．the biggest |
An elephant is_____ than a tiger.
| A．heavy | B．very heavy | C．the heavier | D．heavier |
It is _____today than yesterday. Shall we go swimming this afternoon?
| A．the hotter | B．hot | C．hottest | D．hotter |
The Changjiang River is _____ than any other river in China.
| A．shorter | B．longer | C．the shortest | D．the longest |