第12题: [单项选择]Your dog needs at least 20 minutes of vigorous exercise every day. A. energetic B. free C. physical D. regular 参考答案:A 答案解析:[解析] vigorous和energetic都表示“有活力的、精力充沛的”;free:自由的;physical:体力的、身体的;regular:定期的、正式的。
第13题: [单项选择][*] 参考答案:A 答案解析:[解析] Mr. Smith wants to visit the Great Wall very much.