You are given a sentence and your task is to generate another sentence that supports the given input.
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Question: When the parallel rays of a light source strike a convex lens the rays will concentrate or focus at a specific point, the focal point .

Answer: Convex lenses are thicker in the middle than at the edges so they cause rays of light to converge, or meet, at a point called focus.

Question: The life cycle of all plants is complex because it is characterized by alternation of generations.

Answer: The life cycle of plants is so complex because of the alternation of generation.

Question: As alternating current moves back and forth in a wire, magnetic fields are created around the wire.

Answer:
Alternative current is produced when a magnet or coil moves back and forth repeatedly.