___ the problems are numerous, we must still try to solve them.
A.in spite of
B.although
C.in order that   
D.since

“You can’t have this football back ___ you promise not to kick it at my cat again”, the old lady said firmly.
A.while
B.until    
C.when
D.though

Some fish can survive only in salt water, ____ other species can live only in fresh water.
A.since   
B.unless
C.if
D.whereas

___ I had turned the corner, I began to run.
A.scarcely
B.once
C.just
D.hardly

___ you do better work than this, you won’t pass the exam.
A.if
B.although
C.unless
D.when

___ Jackson became famous, he has ignored his old friends. He shouldn’t do that.
A. if
B.ever since
C.even though   
D.due to

He won’t be able to pay for the car ___ his father’s help.
A.until    
B.except
C.unless
D.without

___ efforts to combat it, drug abuse is on the increase.
A.throughout
B.in the event of
C.despite
D.instead of

Some people tell you what they think you want to hear, ___ it is true.
A.whether or not
B.no matter what
C.regardless
D.however

___ the traffic was bad, I arrived on time.
A.although
B.in spite of
C.despite
D.even