【C5】A．beforeB．whileC．whenD．after

I like climbing mountains______ my brother prefers water sports.A．asB．whileC．whenD．for

【C18】A．becauseB．whileC．whenD．if

【C5】A．beforeB．thatC．soD．until

【C5】A．whichB．whereC．whenD．whether

【C4】A．beforeB．asC．whenD．while

【C5】A．SinceB．After a whileC．AgainD．Before long