Don’t promise anything ______ you are one hundred percent sure.
| A．whether | B．after | C．how | D．unless |
My school isn't far from here. It's only ________ walk.
| A．fifteen minutes | B．fifteen minutes' | C．fifteen minute's | D．fifteen minute |
— Who is in the reading room? The lights are all on.
— ___________.
| A．Nothing | B．None | C．No one | D．No |
The conference has been held to discuss the effects of tourism _______ the wildlife in the area.
| A．in | B．on. | C．at | D．with |
He went out without an umbrella , __________ in the rain.
| A．risked being caught | B．risking being caught |
| C．risked to be caught | D．risking to be caught. |
I wish I ___________ the star last night.
| A．saw | B．were to see | C．had seen | D．did see |