Jerry has promised to keep the secret, so he won't tell anyone ________ asked to.
A．until B．now that
C．unless D．even though
The movie Life of Pi is so attractive that it holds the audience's curiosity ________ the story reaches the end.
A．until B．before
C．after D．when
________ H7N9 is a deadly virus, it is still safe to eat thoroughlycooked chicken.
A．Until B．While
C．If D．Since
I will accept Guy coming with us, ________ he pays for his own meals.
A．only if B．so that
C．ever since D．even though
Scientists are warning that ________ emissions of carbon (碳排放) are cut, we could be heading for an environmental disaster.
A．before B．as
C． unless D．in case
——Did you inform Helen of the plan put forward at the meeting?
—Of course. ________ I saw her.
A．So long as B．If only
C．The moment D．Any time
