属于北朝的科学家有
①贾思勰②祖冲之③郦道元④张衡[ ]
A.①②
B.③④
C.①③
D.②④
答案:C
As a conductor, Leonard Bernstein is famous for his intensely vigorous and exuberant style.
A.extreme
B.enthusiastic
C.prosperous
D.nervous
渣中的P2O5对钢包炉衬侵蚀的影响最大。