________ eating some sugar is necessary, eating too much can be harmful to one's health.

A．Whether 

B．Since

C．While 

D．If

In rugby (橄榄球)，the ball is usually carried forward by players, ________ kicking is permitted.

A．so

B．in case

C．so that

D．though

Our government has taken some measures to overcome the lack of electricity, but it may take some time ________ we have enough power.

A．since 

B．after

C．unless 

D．before

Medicine shouldn't be kept ________ it is accessible to children.

A．even if 

B．which

C．where 

D．so that

I thought we'd be late for the concert,________ we ended up getting there ahead of time.

A．but

B．or

C．so

D．for

She is a crazy fan of this singer. ______ she listens to his songs hundreds of times, she will never get tired.

A．If 

B．As long as

C．Unless 

D．Even if

The young couple are trying to save as much as possible ________ they can afford a flat by the end of next year.

A．so that 

B．even though

C．in case 

D．as if

The boys are still playing basketball happily on the court ________ it is raining heavily.

A．in case 

B．even though

C．as if 

D．as long as

________ one is fully prepared, outdoor sports can sometimes mean injuries.

A．Until 

B．Because

C．When 

D．Unless

________ you've tasted it, you can't imagine how delicious the dishes I cooked are.

A．Because 

B．Unless

C．Although 

D．When