See if you can solve these rebuses which range from easy to hard. They are all linked by a topic.

1. On e

2. luu (-4)

3. 

4. 

5. 
   
   

EDIT:

Hints:

2. I could have added a space to make it make easier.

4. Treat the 4+image as one unit. Keep reading it aloud.

5. rlord3534 has the interpretation for the 3 images correct. Now see if you can make sense of them. It would help if you keep thinking about what exactly you are trying to solve.

_{*Note the images of the flags, bus, spring, trophy outline and the text for 'tumn' do not belong to me (all obtained online).}