【C5】A．becauseB．ifC．thoughD．when

【C18】A．BecauseB．IfC．AlthoughD．Unless

【C16】A．becauseB．even ifC．sinceD．if

【C12】A．AsB．As ifC．ThoughD．Unless

【C6】A．UnlessB．IfC．ThoughD．As

【C9】A．becauseB．ifC．thoughD．when

A.becauseB.unlessC.thoughD.until