We can't wait any longer ________ we'll miss the plane.
A.or B.but
C.so D.yet
House prices vary from place to place and are usually high ________ there are famous schools.
A.when B.since
C.where D.whether
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
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