He began to take political science_____ only when he left school. 

My parents always remind me to make sure the electricity is turned off while I am having a bath, which would _____________ cause danger, leading to a dreadful consequence.

I thought it would be rainly that day, but it ___ to be fine.

---- Do you think it's a good idea to make friends with your students? ---- _____ , I do．I think it's a great idea．

______, I love soft music more than popular music.