-John has put forward _______ most challenging question for us to answer.
-Yes, it really is. I have never heard _______ harder one.
A．the; 不填 B．不填; the
C．the; the D．a; a
I often have conversations with John over ______ telephone, while keep in touch with Tom by ______ letter.
A．不填；the B．不填；a
C．the；不填 D．the; a
考点：冠词
The education of ______ young is always ______ hot and serious topic.
A．不填, 不填 B．the, a
C．不填, the D．the, 不填
As _______ unemployment is very high at the moment, it's very difficult for people to find _______ work.
A．the, 不填 B．不填，不填
C．the, a D．an, the
He spent too much time talking on ______ phone while we were all busy at _____ work.
A．the, 不填 B．a, 不填
C．不填, 不填 D．the, the
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
