The blind man who ________ by a car ________ to hospital．
A.knocked over; was sentB.was knocked at; was sentC.knocked into; will be sentD.was knocked down; must be sent在线课程D
解析：
knock down撞倒。从句子的结构上看，应该用被动语态，第一空为过去时的被动语态，第二空为情态动词的被动语态。