- we cant see rainbow as night as their is no refraction of sun light as sun is   not present at night and hence we cannot able to see rainbow at night.

- no it has to be continuously fly while it was in air

- this is just a silly question water is wet

- sun is the only star that can be seen at day time because the sun releases a huge amount of sunlight due to which we cannot able to see any other stars  sun  light is very bright. so we cannot able to see other stars during the day time.

hope this will help you and plz mark my answer as brainliest