脑卒中深静脉血栓形成的高峰期是（）
A.1周内
B.1个月内
C.2个月内
D.3个月内
E.半年内
参考答案：A
---- Each year __________ fishes are killed by the polluted water and many people are made sick by the polluted air .
----So we should do something to stop it .
A．millions of
B．million of
C．two millions of
D．two millions
一般情况下，随着更多的证券加入到投资组合中，投资组合的整体风险降低的速度会越来越慢。 ( )
