我国年降水量分布的总趋势是( )
A:从西南向东北递减
B:从西北内陆向东南沿海递减
C:从东南沿海向西北内陆递减
D:从东北向西南递减
“百折不挠”、“绳锯木断”、“水滴石穿”、“锲而不舍”这些成语体现了良好的意志品质具有 。()
—Excuse me, sir, visiting hours are over. You leave.
—Pardon me, nurse. I didn't hear the bell.
我国提倡18﹣55周岁的健康公民自愿献血,一次献血多少不会影响身体健康( )