A．thoughB．butC．forD．since

【C4】A．andB．butC．sinceD．while

【C18】A．thoughB．whileC．beforeD．until

A．thoughB．whetherC．thusD．how

【C12】A．exceptB．butC．forD．on

【C8】A．thoughB．whileC．so thatD．as

【C3】A．ThoughB．SinceC．WhileD．Once