СРОЧНО!!!!!!
A: How (break, you) your arm?
B: I (slip) on the ice while I (cross) the street in front of the dorm.

Ответ:

How did you break your arm?

I slipped on the ice while I was crossing the street in front of the dorm.

Объяснение:

Ответ:

A: How did you break your arm?

B: I slipped on the ice while I crossing the street in front of the dorm.