纵隔恶性淋巴瘤有以下表现,错误的是()。
A.上纵隔增宽呈波浪状
B.常多组淋巴结受累
C.常有包膜钙化
D.可侵犯心包
E.向肺内浸润呈线状、小结节状
参考答案:C
Peter hurried through dinner, changed into old clothes, _______ in the lab for three hours.
A.worked
B.working
C.and worked
D.to work
为什么货车要采用两级刚度弹簧?