问题
选择题
选择填空。
Is your brother good at ______?[ ]
A. sing
B. to sing
C. sings
D. singing
答案
答案：D
搜题请搜索小程序“爱下问搜题”
选择填空。
Is your brother good at ______?[ ]
A. sing
B. to sing
C. sings
D. singing
答案：D
25钢筋，两端用螺丝端杆锚具，采用60t拉伸机张拉，构件孔道长23.8m，试计算钢筋下料长度。