【C3】A．BecauseB．AsC．SinceD．Although

【C16】A．becauseB．even ifC．sinceD．if

【C16】A．BecauseB．WhenC．BeforeD．Although

【C5】A．SinceB．AsC．ThereforeD．Although

The oil must have been used up,______the light went out.A．becauseB．forC．sinceD．as

【C3】A．henceB．yetC．sinceD．that

【C8】A．BecauseB．HoweverC．NeverthelessD．Although