The problem just ______to be discussed.
| A．referred is | B．referred to be | C．referring to is | D．referred to is |
Auckland is a most exciting city with people of many different cultures ______ there .
| A．live | B．having lived | C．lived | D．living |
The old town has narrow streets and small houses _______ are built close to each other .
| A．in which | B．where | C．what | D．that |
We have made _______great progress in the medical field, but ______ progress we have made is not enough.
| A．a; a | B．a; the | C．/; the | D．/; / |
I have many foreign friends, some are businessmen.
| A．of them | B．from which | C．who of | D．of whom |
He used to ______ cards, but now he is used to _______ a walk after supper.
| A．play; taking | B．playing; take | C．play; take | D．playing; taking |