题干
In the second paragraph, we know ____________.
A：a good habit of running may help you live longer
B：the number of non-runners was getting smaller
C：three quarters of 55,000 adults were new to running
D：the hope to live three years longer drives people to exercise
答案(点此获取答案解析）
A
、“6V，6W”的灯泡
与理想电压表和理想电流表连接成如图（a）所示的实验电路，其中电源电动势E=9V，图（b）是通过两个灯泡的电流随两端电压变化的曲线，当其中一个灯泡正常发光时（ ）