You never play the piano well _________you practice it again and again.
A.if B.since
C.unless D.after
一Did you catch what our head teacher said?
一Sorry,I _________ a phone.
A.will answer B.am answering
C.have answered D.was answering
一I don't know _________ she can't go hiking with us.
一She has to do her homework.
A.when B.if
C.why D.how
一_________will the fog and haze last?
一I've no idea.there is no sign of an end.
A.How soon B.How far
C.How long D.How often
My little cousin is a(an) _________ boy and he always asks me all kinds of strange questions.
A.creative B.serious
C.patient D.helpful
A person's life is like a road _________lots of difficulties.We must face it bravely.
A.by B.with
C.along D.during