— Have you found your English book?
— I am not sure ____ I could have left it.
| A．whether | B．what | C．when | D．where |
Into the sky______the light blue smoke.
| A．had gone up |
| B．up went |
| C．did go up |
| D．went up |
He glanced out of the window，______ that the post office was still closed.
| A．noted | B．having noted | C．to note | D．noting |
Her mother does not ______ of her going to study in the United States alone.
| A．admit | B．agree | C．prove | D．approve |
—Are train services now back to ______after last week's snowstorm?
—Yes，they are.
| A．ordinary | B．normal | C．common | D．average |
He told this to somebody else，not realizing that he ______.
| A．didn't suppose | B．was not supposed |
| C．didn't suppose to | D．was not supposed to |