—Hi , Tracy , you look tired. —I’m tried. I ______ the living room all day.
| A．painted | B．had painted | C．have been painting | D．have painted |
It's said to be a case of murder ________ the children were used by adults.
| A．when | B．where |
| C．which | D．that |
Naturally a smile ________ the eyes participate is extremely communicative.
| A．to which | B．in which |
| C．at which | D．with which |
With hundreds of attractions, Beijing is a city ________ makes a lasting impression on its visitors.
| A．which | B．where |
| C．what | D．when |
Just use this room for the time being, and we'll offer you a larger one ________ it becomes available.
| A．as soon as | B．unless |
| C．as far as | D．until |
Everything was placed exactly ________ it used to be before she left the laboratory.
| A．why | B．when |
| C．where | D．though |