单选题 Before the final exam, many students have shown ______ of tension (紧张). Some have trouble in sleeping while others have lost their appetite (胃口).

【正确答案】 C
【答案解析】[考点] 词义辨析
[解析] anxiety意为“忧虑”；mark意为“标志”；sign意为“迹象”；remark意为“评论”。由题意可知应选C。