New buildings in earthquake-prone areas must be heavily reinforced or else they may otherwise collapse in a strong quake.
1 or else they may otherwise collapse in a strong quake
2 or they may collapse in a strong quake
3 so as not to collapse in a strong quake
4 not to collapse in a strong quake
5 or else it may collapse in a strong quake
I selected 3 . Y is it wrong?
1 or else they may otherwise collapse in a strong quake
2 or they may collapse in a strong quake
3 so as not to collapse in a strong quake
4 not to collapse in a strong quake
5 or else it may collapse in a strong quake
I selected 3 . Y is it wrong?












