A:π6 或 5π6
B:−π3 或 π3
C:−π6 或 π6
D:π6
已知黑光灯的功率为30W,若每晚工作时间为10小时,则每晚消耗____ 电能.
He fell off the bike and hurt his leg yesterday._______, he had to stay at home for two or three months.
写出整理资料的步骤。