单选题 Mary had taken pains to ______that her guests had everything they could possibly want.
【正确答案】 A
【答案解析】[解析] 词汇意义辨识与使用。take pains to意思是“小心谨慎地做事”，再根据后半句的意思，只能是自己去观察，看到，所以选A。