I will go to visit my aunt in England ______ the summer holiday starts.
| A．while | B．since |
| C．until | D．as soon as |
The little boy is only six years old, _________ he can make wonderful model cars.
| A．so | B．or | C．but | D．/ |
Please knock at the door ________ you come into the room.
| A．before | B．after | C．until | D．while |
A tourist will easily lose his way in Beijing ______ he has a map or a guide.
| A．if | B．because |
| C．unless | D．when |
Be quick, ＿＿＿we’ll be late for school.
| A．and | B．or | C．so | D．/ |