Generally speaking, _____ according to the derections , the drug has no side effect.
| A．when to take | B．when taking | C．when to be taken | D．when taken |
Last night he saw two dark __________ enter the building, and then there was the explosion.
| A．features |
| B．characters |
| C．images |
| D．figures |
-Have you __________ how much the trip will cost?
-I'm working on it; just have a little patience.
| A．added to |
| B．counted on |
| C．added up to |
| D．figured out |
The news shocked the public，__________ to great concern about students' safety at school.
| A．having led |
| B．led |
| C．leading |
| D．to lead |
Plastic bags are provided for our convenience but they have also __________ the pollution of the environment.
| A．referred to |
| B．led to |
| C．reacted to |
| D．attended to |
Look over there-there's a very long, winding path __________ up to the house.
| A．leading |
| B．leads |
| C．led |
| D．to lead |