Is some American friends visited last week?
| A．this school | B．this the school |
| C．this school one | D．this school where |
My boss hates interruptions,when he is trying to work.
| A．occasionally | B．generally | C．specially | D．especially |
Mother always tells me to believe in myself, ____ that nothing is too difficult to a willing heart.
| A．to say | B．saying | C．said | D．having said |
In order to understand the____ of the animal, she spent many years recording its daily activities.
| A．performance | B．deed | C．behavior | D．personality |
Only after the woman had her own child ___ how difficult it was to be a mother.
| A．she realized | B．had she realized | C．she had realized | D．did she realize |
I would appreciate ________ much if you could write to me as soon as possible.
| A．that | B．it | C．this | D．what |