Question

It is Mary's brother who_____(be) injured in the car accident yesterday.

Answer 1

您好！很高兴为您解答！
填was who引导的强调句，强调句句式：it is +that，yesterday表示动作发生在过去，所以用一般过去时，injured跟Mary`s brother构成被动关系，所以要用被动，所以填was
翻译：昨天在车祸中受了伤的是玛丽的弟弟/哥哥

希望可以帮到您，祝您成功！

Answer 2

was
it is...that/who...强调句，做题时可以把它省略，直接看成 Mary's brother _____(be) injured in the car accident yesterday. 第三人称单数的过去式，用was。

Answer 3

It is Mary's brother who__was___(be) injured in the car accident yesterday.
【解析】考察“it is + N.+that”强调句结构
后面yesterday，故用一般过去时，填was

满意请采纳
O(∩_∩)O~

Answer 4

was
强调句型 it's....that/who....被强调内容为Mary's brother(单数第三人称）yesterday为过去时。