单选题 She was extremely ______ about expressing her opinions.
A. cautious B. careful C. worried D. cautionary

【正确答案】 A
【答案解析】[解析] cautious意为“十分小心谨慎的”；careful“仔细的，小心的”，后面跟with而不跟about；worrled意“焦虑的，担心的”；cautionary意为“给以忠告的”。这两个词放入题中都说不通。