当钢结构的焊缝形式、断面尺寸和辅助要求相同时，钢结构图中可只选择一处标注焊缝，下列哪一个表达形式是正确的().
A.A
B.B
C.C
D.D
参考答案：A
Jack prefers _____ his old car _____ a new one. [ ]
A. selling; to buy
B. selling; to buying
C. to sell; to buy
D. to sell; buy
500.05读作五百点五．______．
