— Miss Li, where did you visit last week? 

— I visited a big company ______ ships are made. [ ]

A. that

B. which

C. where

D. whose

多普勒超声技术可分为（）。

A.脉冲多普勒

B.彩色多普勒

C.连续多普勒

D.频谱多普勒

E.组织多普勒