My brother_________(snowboard)when he_________(break)his leg in several places
问题描述：
My brother_________(snowboard)when he_________(break)his leg in several places
答
My broter was snwboarding when he broke his leg in several places
答
My broter was snwboarding when he broke his leg in several places
考查了过去进行时的用法
我哥哥摔断腿时正在滑雪.
WHEN引导的时间状语从句是过去发生的,所以从句要用一般过去时
而有了这个从句,时间状语构成一个时间点,在那一点上正在发生这件事,要用进行时态,由于是过去发生的所以是过去进行时