The chemical reaction proceeds at an invariable rate under controlled temperature and pressure conditions.
在受控的温度和压力条件下，该化学反应以恒定速率进行。
Which choice best defines “invariable”?
B — Never changing; constant.. “invariable” means Never changing; constant..
Which word means “Never changing; constant.”?
B — invariable. “invariable” means Never changing; constant..
invariable — Never changing; constant.. In Chinese: 不变的;恒定的.
invariable is pronounced //ɪnˈveəriəbl//.
The chemical reaction proceeds at an invariable rate under controlled temperature and pressure conditions. (在受控的温度和压力条件下，该化学反应以恒定速率进行。)
constant, unchanging, uniform — all close in meaning to invariable (Never changing; constant.).
variable, changeable — each the opposite of invariable (Never changing; constant.).
Yes. invariable is on the SAT Prep Difficult list — the higher-register words that decide the hard questions. 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(不) + variable(可变的) → 不会变 → 恒定的。