We can never expect ______ bluer sky unless we create _______ less polluted world.
| A．the; a | B．a; a | C．the; the | D．a; the |
In those days, we had no phones, so we have to keep in touch _____ writing often.
| A．with | B．of |
| C．on | D．by |
Don’t be angry _______ me for not having written. I was really too busy.
| A．about | B．with |
| C．to | D．for |
“When did you leave the farm?” “____ the end of last year.”
| A．In | B．By |
| C．At | D．Since |
“How long will you work on the farm?” “____ the end of next year.”
| A．In | B．By |
| C．At | D．Since |
“How long will you work on the farm?” “____ the end of next year.”
| A．In | B．By |
| C．At | D．Since |