— Thank you for your coffee. I'm afraid I have to be off now.
— OK, _______.

    Here comes the last term of Junior 3. Terrible! The big exam is coming in less than two months. You still have a lot to do. How will you spend it? We invited three students to share their stories.
Dou Yi, 15,Beijing
    My chemistry  used to be poor in the past. I got scores of around 40 on every test. During the last term, I decide to beat chemistry. I will start to work hard. In class I take every possible note. After school, I spend most of my time studying chemistry. My parents also ask their friend, a chemistry teacher, to help me . Finally in the latest exam, I got 65! How happy I am!
Wang Zhaolin, 16, Chongqing
    My foot got hurt a week before the big PE exam . Luckily, I recovered（康复） in time. For PE , all you need is to practice. Sports can also help you relax. Be careful not to get hurt as I did.
Wang Feixuan, 15, Xi'an
    My experience is that for Junior3, every minute of the last term is important. Don't waste any of them. I try to remember English words while waiting in line to get my lunch. I read textbooks on the bus to and from school. I work hard at home and sometimes stay up late studying. Want to have fun? Leave it for the summer holiday after the big exam!

下列能体现“母法与子法”的关系的是（　）

材料一：贸易保护的形式多样，除关税保护外，还有外汇管制、卫生检疫、环保标准和技术标准等。1841年弗里德里希•李斯特发表《政治经济学的国民体系》，强调国家在经济生活中的重要作用，论证了实行关税保护发展民族工业的必要性。从19中后期起，美国绝大部分时间都是共和党人入主白宫，他们是工商业的政治代言人，要求提高关税，限制外国廉价劳动力制造的商品进入美国，降低竞争，保障美国工人的就业率和高工资，促进美国经济发展。此时，加拿大、意大利、德国、法国、日本等纷纷颁布关税保护法。1821—1897年美国关税平均税率是：1821—1824年为44.62%，1825—1832年为50.92%，1833—1857年为35.1%，1864—1866年为48.3%，1897年为57.00%。

——摘编自褚浩《19世纪后期美国贸易保护政策研究》

材料二：关税自主成为近代中国对外贸易的关键。近代以来我国对外贸易连年遭受损失，入超现象相当严重。民国时期的工商界人士十分重视关税对贸易的保护作用，解决这个历史遗留问题始终成为当时中国人的梦想。1917年北洋政府国定进口税则、还通过巴黎和会、华盛顿会议、关税特别会议等与列强力争关税自主。南京政府通过多次修约，与列强艰难周旋，最终在形式上和法律上确立了关税自主的地位。

——摘编自罗希红《民国时期对外贸易政策特殊分析》