肾病综合征时,产生水肿的主要始动因素是 ()
A.毛细血管滤过压增高
B.毛细血管通透性增高
C.水与钠潴留
D.血浆胶体渗透压降低
E.淋巴液回流受阻
参考答案:D
起重机的钢绳将500N的物体匀速提高6m后,又水平匀速移动4m,钢绳对物体所做的功为______.
下面可以正确定义2个整型变量和1个字符串变量的语句是【 】
A.Dim n,m As Integer,s As String
B.Dim a%,b$,c As String
C.Dim a As Integer,b,c As String
D.Dim x%,y As Integer,z As Suing