Fill in the correct conjunction: because, but, and, after, before, while,

Fill in the correct conjunction: because, but, and, after, before, while, when, if.

You may have several correct answers. Put a slash to seperate correct answers. If the sentence begins with that conjunction, do not forget to write it with a capital letter.

Example: Please turn off the lights _____ you go to bed.

Answer: before/when

_____ my brother was reading in the car I was watching the planes.

Answer:
?