when / while

The mouse was running across the room ____ the cat saw it.

• while

• when

____ the cat saw the mouse, he started chasing it.

• when

• While

___the little mouse was running across the room, she saw the cat!

• when

• while

The poor mouse panicked ____ she saw the cat.

• when

• while

___ the mouse panicked, she began to run faster.

• when

• while

The cat also ran faster____ he saw the mouse go faster.

• when

• while

___ the cat and mouse were running across the room, a bird flew in the window.

• when

• while

____ the bird flew in the window, the cat jumped at the bird.

• when

• while

____ the cat was still flying through the air to catch the bird, the bird flew out the window.

• when

• while

The lucky mouse ran away ___ the cat was trying to catch the bird.

• when

• while