To test the mixture's stability, the chemist carefully inverted the sealed flask and observed whether any sediment settled to the top.
为了测试混合物的稳定性，化学家小心地倒转密封的烧瓶，观察是否有沉淀物浮到顶部。
Which choice best defines “invert”?
C — To turn something upside down or inside out. “invert” means to turn something upside down or inside out.
Which word means “to turn something upside down or inside out”?
D — invert. “invert” means to turn something upside down or inside out.
invert — to turn something upside down or inside out. In Chinese: 使颠倒，倒转.
invert is pronounced /ɪnˈvɜːrt/.
To test the mixture's stability, the chemist carefully inverted the sealed flask and observed whether any sediment settled to the top. (为了测试混合物的稳定性，化学家小心地倒转密封的烧瓶，观察是否有沉淀物浮到顶部。)
reverse, overturn, upend — all close in meaning to invert (to turn something upside down or inside out).
upright, right — each the opposite of invert (to turn something upside down or inside out).
Yes. invert is on the SAT Prep Easy list — mid-frequency academic words that do get tested. The Digital SAT does not test vocabulary in isolation; words like this one are tested through Words in Context questions, where you choose the word that completes a passage most logically and precisely.
in-(into) + vert(turn) → to invert, change direction.