单项选择题
作为基坑围护结构主体的工字钢，一般采用（）号大型工字钢。
A．30 B．35 C．40 D．50
单项选择题 Who was Miss Fanny Jackson
单项选择题 Robert Spring spent 15 years ______.
单项选择题 Why did Spring sell his false autographs in England and Canada
