I didn't write to you because______your address.要写为什么哟,

I didn't write to you because______your address.要写为什么哟,
I didn't write to you because______your address.要写为什么哟,

I didn't write to you because______your address.要写为什么哟,
I didn't write to you because I have forgotten your address
Or 说I forgot your address也是okay的

如果不限字数应该是 I don't know ，如果字数有限就得去问老师了。 至于为什么这么填，逻辑问题，不解释。