These days it is found that school students hardly have any sports. Is it because they have no 1 in sports? It may not be true. They often say they have 2 more important things to do.

    What are these important things? Exams! They have to 3themselves ready for all kinds of exams and tests in school. So many of them almost4bookworms(书呆子). In the past in the summer holidays, they could do5 they liked, but now they have to 6all their time preparing. So 7 have kept them away from going in for sports.

    Because of the pressure(压力) from 8 parents and teachers, they  9 to work harder and spend most of their time10 books. As for the students themselves, they don't want to11 the lessons because they want to further their studies. So it is necessary to give 12 of their spare time to their studies and 13 up their school sports.

    It's true a good education cannot go without physical training, the14 is true a quick mind hardly goes along with a 15body. Without a strong body, you can never do anything well, how can you make great success in life?

如图甲是某金属材料制成的电阻R随摄氏温度t变化的图象，图中R₀表示该电阻在0℃时的电阻值，已知图线的斜率为k  。若用该电阻与电池（电动势为E、内阻为r）、理想电流表A、滑动变阻器R′  串联起来，连接成如图乙所示的电路。用该电阻做测温探头，把电流表A的电流刻度改为相应的温度刻度，就得到了一个简单的“金属电阻温度计”。

①根据图甲，温度为t（t>0℃）时电阻R的大小为____。

②如果某次测量时，指针正好指在在温度刻度的10℃到20℃的正中央，则测量值

____ 15℃（填“大于”、“小于”或“等于”）。