People who talk and sing to plants are not crazy, according to Arnold Braymar, a government agriculture expert. "In fact, singing and talking to plants makes them grow better," says Braymar. The reason is quite simple—when we sing or talk to plants, we exhale carbon dioxide which plants need to survive and thrive. Plants absorb the carbon dioxide through their pores during the sunlight hours and produce oxygen which people need to survive. Singing and talking is effective, however, only during the daytime. Bedtime lullabies will not help plants to sleep better or grow faster.

Q. Circle the outline which illustrates the structure of the paragraph and underline the topic sentence: ▼ ▲ ♦ ▊.