Jawaban:

1. The purpose of the text is to provide information about rainbows, including their causes, appearance, and types.
2. The text is structured in a descriptive and informative manner, providing information about rainbows in a logical sequence. It begins with a definition of what a rainbow is and how it is formed, followed by a description of the appearance of rainbows and how they are observed. The text then goes on to explain the different types of rainbows and their causes.
3. "Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun." (present simple tense)

Penjelasan:

A rainbow is a meteorological and optical phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun.

Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground,[1] and centered on a line from the Sun to the observer's eye.

In a primary rainbow, the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it.

In a double rainbow, a second arc is seen outside the primary arc, and has the order of its colours reversed, with red on the inner side of the arc. This is caused by the light being reflected twice on the inside of the droplet before leaving it.