用适当的介词或副词填空。
1、She often complains ( ) working overtime.
2、The minute the gun went ( ) ,the people ran away in all directions.
3、All the books borrows from the library must be brought ( ) before June 20.
4、Every day I switch ( ) the TV at seven o'clock and switch ( ) to CCTV Channel One to watch the news.
谢谢。
