| " ______ do you write to your parents?" "Once a month." |
A. How long B. How much C. How far D. How often |
| Mike _____ his homework three hours ago. |
A. finished B. has finished C. is finishing D. is going to finish |
| David was born _____. |
A. since twenty years ago B. for twenty years C. twenty years ago D. just over twenty years |
| — Do you know ______ the Capital Museum? — Next Friday. |
A. when will they visit B. when they will visit C. when did they visit D. when they visited |