计算cos245°+tan60°cos30°的值为____ ．
“父死子继，兄终弟及”是我国王位世袭制的典型特点，标志着我国王位世袭制代替禅让制的是( )
Good news! We'll have ____ one-day holiday in order to celebrate the 70th annzversary（纪念日）of the victory in World War II.
下列实验基本操作正确的是（ ）
