【C8】A．unlessB．sinceC．ifD．though

【B15】A．whenB．asC．ifD．though

A．unlessB．beforeC．thusD．until

【24】A．providedB．sinceC．whereasD．though

【C8】A．likewiseB．FurthermoreC．WhereasD．Even though

【C8】A．SinceB．AsC．IfD．Though

【C7】A．unlessB．otherwiseC．ifD．because