________ H7N9 is a deadly virus, it is still safe to eat thoroughly?cooked chicken.

A．Until B．While

C．If D．Since

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

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

It will be another 50 years ______ our country is expected to reach the level of a medium developed country.

A．since B．before

C．that D．when

House prices vary from place to place and are usually high ________ there are famous schools.

A．when B．since

C．where D．whether

We can't wait any longer ________ we'll miss the plane.

A．or B．but

C．so D．yet

The new system needs to be in operation for five months ________ it can be updated.

A．as B．while

C．before D．once

________ it is, the boy never seems to be able to finish it off.

A．However interesting a book

B．Whatever interesting a book

C．How interesting a book

D．What an interesting book

Steve was busy clearing the cups and dishes from the table ________ others were playing.

A．until B．if

C．since D．while

You seem to have a ready?made answer ________ I ask you a question.

A．whenever B．whatever

C．whichever D．whoever