A:20cm2
B:20πcm2
C:15cm2
D:15πcm2
选出错误项并改正
He was too tired that he couldn't keep his eyes open.
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读我国某农村人口年龄结构金字塔图,完成下列问题。
某同学早上起床时每分钟心跳次数为80次,那么在他跑步的过程中,心跳的次数可能为( )