— May I go and play with Dick this afternoon, Mum?
No, you can’t go out _______ your work is being done.
| A．before | B．until | C．as | D．the moment |
So little _____ with each other that the neighboring countries could not settle their differences.
A. they agreed B agreed they C. did they agree D. they did agree
Martin Cooper , a US researcher , was considered _______ the first cell phone .
| A．invented | B．to invent | C．having invented | D．to have invented |
He looked around and caught a man _____ his hand into the pocket of a passenger.
| A．put | B．to be putting | C．to put | D．putting |
They walked together as far as the second crossing ____ they parted .
| A．when | B．which | C．why | D．where |
You may use my bike _____ that you return it by noon.
| A．on condition | B．in condition | C．under condition | D． at conditions |