There is no doubt the earth is becoming warmer.
| A．whether | B．that | C．if | D．why |
As is known to us all, _____ tiger is in _____ danger of becoming extinct.
| A．the, a | B．the, 不填 | C．a, 不填 | D．不填, the |
This is _____ best kind of _____ pen you can get here.
| A．the, the | B．the, a | C．the, 不填 | D．a, the |
How strange! These years my birthday always falls _____.
| A．on the Sunday | B．on a Sunday |
| C．on Sunday | D．at a Sunday |
As _____ writer, he was _____ complete failure.
| A．a, a | B．a, the | C．不填，不填 | D．a, 不填 |
This is _________ best kind of _________ pen you can get here.
| A．the, the | B．the, a | C．the, 不填 | D．a, the |