. ______ is quite natural; a beginner can't read the books written in English very quickly.
| A．Which | B．As | C．What | D．It |
He is so busy.He cannot afford enough time with his son________he wants to.
| A．even if | B．as if | C．because | D．before |
I have heard a lot of good things about you ________ I came back from abroad.
| A．since | B．until | C．before | D．when |
________I have to give a speech，I get extremely nervous before I start.
| A．Whatever | B．Whenever | C．Whoever | D．However |
Mark needs to learn Chinese________his company is opening a branch in Beijing.
| A．unless | B．until | C．although | D．since |
One can always manage to do more things，no matter________full one's schedule is in life.
| A．how | B．what | C．when | D．where |