▍原文 Some research suggests that chewing gum may help some people concentrate and learn. In a 2018 study of 40 adults, researchers found that those who chewed gum while presented with physiology lessons performed better on tests afterward than those who didn’t chew gum. Many gums are made using plastics like polyethylene and polyvinyl acetate, Dr. Arsenault said. This helps give gum its elasticity. These plastics can be released into our mouths, but it’s unclear how that affects health. ▍語言點 1. perform /pərˈfɔːrm/ v. 表現 The car performs well in cold weather. 車在冷天性能好。 perform badly on stage 在舞臺上表現糟糕 2. present /ˈpreznt/ v. 呈現；展示 · present something to somebody / somebody be presented with something 向某人展示、呈現某物 3. polyethylene /ˌpɑːliˈeθəliːn/ n. 聚乙烯 · 前綴poly-表示 “多、聚；聚合”” · polygamy n. 多偶制 · polyglot adj. 通曉多種語言的 4. polyvinyl acetate 聚乙酸乙烯酯（縮寫為 PVA） 5. elasticity /ˌilæ...