I __________ for five minutes, why don't they come?
| A．am waiting | B．waited | C．was waiting | D．have been waiting |
____ four years since I joined the Army.
| A．There was | B．There is | C．It was | D．It is |
The climate of Shanghai is better than ____ of Nanjing.
| A．that | B．it | C．which | D．what |
We think ____ our duty to pay taxes to our government.
| A．that | B．this | C．its | D．it |
____ will do you good to do some exercise every morning.
| A．It | B．There | C．Those | D．You |
The color of my coat is different from ____ of yours.
| A．this | B．that | C．it | D．one |