The essays by foreign students are well-written ______ some spel

The essays by foreign students are well-written ______ some spelling mistakes?
A、beside
B、besides
C、except
D、except for
【正确答案】：D
【题目解析】：except for 1.除了…外；除去,撇开,只是 2.要不是(由于),若无,除非[亦作 but for；句意：外国学生的作文写得很好，只是有几处拼写错误。