I want to ring him＿＿＿to know the reason why he rang＿＿＿while I was speaking yesterday. 

History is the best teacher. It _______records the development path of each country and foretells the future to us.

— Lovely weather, isn’t it?— Yes, a bit hot, ______ ．

I lost my wallet last week, but ____ it didn’t contain much money at that time.

Passengers will likely face the usual struggle to get their tickets during festivals, __________ at railway stations, where long lines are expected.