燃气涡轮发动机涡轮转子叶片受到连续的高温和离心力可能引起（）.
A.划伤
B.压坑
C.烧蚀
D.蠕变
参考答案：D
My cousin _____ about an hour _____ her homework. [ ]
A. spend, do
B. spends, do
C. spend, doing
D. spends, doing
单层工业厂房为保证山墙的稳定性，应在山墙内侧设置（）
A.柱间支撑
B.承重柱
C.抗风柱
D.吊车梁
