__________ something unexpected happens，I will meet you at the school gate tomorrow
morning.
| A．When | B．Unless | C．Since | D．If |
Only when you can find peace in your heart _____good relationships with others.
| A．will you keep | B．you will keep | C．you kept | D．did you keep |
Since the time humankind started gardening, we _____to make our environment more beautiful.
| A．try | B．have been trying |
| C．are trying | D．will try |
There is no greater pleasure than lying on my back in the middle of the grassland, _____at the night sky.
| A．to stare | B．staring | C．stared | D．having stared |
You will never gain success________ you are fully devoted to your work.
| A．when | B．because | C．after | D．unless |
— I’ve prepared all kinds of food for the picnic.
—Do you mean we_____ bring anything with us?
| A．can’t | B．mustn’t | C．shan’t | D．needn't |