A:铜离子在铜片表面被还原
B:铜是阳极,铜片上有气泡产生
C:铜片质量逐渐减少
D:电流从锌片经导线流向铜片
—I'm going to Hawaii with my uncle this month for my holiday.
—______!
(Ⅰ)求 sinα−cosα 的值;
(Ⅱ)求 sin(2α+π3) 的值.