由于青藏高原海拔较高,在修建青藏铁路时将遇到的困难有( )
A:高寒、缺氧、冻土
B:太阳辐射、地震
C:气压高、盐碱化
D:云雾多滑坡
I was studying for the test when the rainstorm came.(对划线部分提问)
____ were you____ when the rainstorm came?