徐变与荷载持续时间t成线性关系……………………………………()
查看答案
What was the woman doing on Friday？
A. Preparing for the calculus exam.
B. Viewing an art exhibit.
C. Participating in a special class activity.
D. Packing for her vacation.
混凝土强度等级由轴心抗压强度确定。()
A. 正确
B. 错误
Who is Ed？
A. The man' s brother.
B. The man' s roommate.
C. A neighbour.
D. A photographer.
混凝土中应力等于零，钢筋产生拉应力…………………………………()
A. 正确
B. 错误
微信支付 
支付宝支付