Do you know ___________ Zunyi or not tomorrow?
A:whether are they leaving for
B:whether they are leaving for
C:if they are leaving for
D:if are they leaving for
步入青春期的信号是( )
给定命题P:若x∈R,则x+1x≥2; 命题q:若x≥0,则x2≥0.则下列各命题中,假命题的是( )
一年中最高月平均气温和最低月平均气温之差为____ .一年中,北半球陆地上最高气温出现在____ 月,海洋上最高气温出现在____ 月;北半球陆地上最低气温出现在____ 月,海洋上最低气温出现在____ 月;南半球相反.