下列古文名句中,可以提醒我们正确对待困境,培养坚强意志的是( )
A:江山代有才人出,各领风骚数百年
B:宝剑锋从磨砺出,梅花香自苦寒来
C:谁言寸草心,报得三春晖
D:飞流直下三千尺,疑是银河落九天
His pronunciation is better, for he kept ______ a short passage after the tape every morning.
已知命题p:∀x≥0,2x≥1;命题q:若x>y,则x2>y2.则下列命题为真命题的是( )