如果a＜0，b＞0，那么ab（ ）0。
＜
It was____of them to have sent the old people and children to safetyin case the flood destroyed
their village. A energetic B considerate C fortunate D patient
海金沙的入药部位是（）
A.干燥成熟的孢子
B.果实
C.带叶嫩枝的干燥煎膏
D.花粉
E.叶上的虫瘿
