影响涡轮使用寿命的因素是：（）.
A.烧蚀
B.变形
C.黏结
D.材料疲劳和腐蚀
参考答案：D
My brother is a football fan, he and his friends _____ make a soccer team next year. [ ]
A. is going to
B. are going to
C. be going to
下述哪项对诊断急性肾小球肾炎最有价值（）。
A.抗"0"增高
B.血沉增快
C.尿沉渣可见红细胞管型
D.C3补体下降
E.蛋白尿
