20世纪80年代，公司债券的发展与金融品种的创新活动达到高峰。值得注意的是，80年代垃圾债券成为一个引人注目的现象。( )
参考答案：对
—John had his hair cut yesterday afternoon, ______?
—______. He had no time and he had to finish his homework first. [ ]
A. haven't he; Yes, he did
B. didn't he; No, he didn't
C. hadn't he; No, he didn't
D. hasn't he; Yes, he has
货车敞车上侧柱截换时须斜接，接口与柱的纵向中心线之夹角不大于（）。
A.45°
B.75°
C.60°
D.80°
