The experiment required researchers to confine the chemical reaction to a sealed chamber to ensure safety.
实验要求研究人员将化学反应限制在密封的舱室内，以确保安全。
Which choice best defines “confine”?
C — To keep someone or something within limits. “confine” means to keep someone or something within limits.
Which word means “to keep someone or something within limits”?
B — confine. “confine” means to keep someone or something within limits.
confine — to keep someone or something within limits. In Chinese: 限制，禁闭.
confine is pronounced /kənˈfaɪn/.
The experiment required researchers to confine the chemical reaction to a sealed chamber to ensure safety. (实验要求研究人员将化学反应限制在密封的舱室内，以确保安全。)
restrict, limit, restrain — all close in meaning to confine (to keep someone or something within limits).
free, release — each the opposite of confine (to keep someone or something within limits).
Yes. confine 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.