---------I hear Johnson was badly injured in the accident.-------let’s go and see him.

问题补充：

---------I hear Johnson was badly injured in the accident.

---------- let’s go and see him.

A. What’s more

B. If so

C. Where possible

D. When necessary

答案：

A. What’s more

(答案→)B. If so

C. Where possible

D. When necessary

解析：if so 为 if it is so 之略，意为“如果那样的话”。