Question

W_________ it's clear or rainy, my parents go out for a walk after dinner every day.

Answer

Whether

【解析】

句意：无论晴天还是雨天，我的父母每天晚饭后都会出去散步。

根据句意无论晴天还是雨天，我的父母每天晚饭后都会出去散步，可知此处表让步，无论whether...or...。故答案填Whether。