31. What does the word "boost" mean when used as a verb?A. To decrease or reduce somethingB. To increase or improve something to make it more successfulC. To maintain something at the same levelD. To completely eliminate something

本题考查对单词“boost”作为动词含义的理解。解题思路是明确每个选项所表达的意思，然后根据对“boost”常见释义的掌握来判断正确选项。

• 选项A：“To decrease or reduce something”意思是减少或降低某物，这与“boost”的常见含义不符。
• 选项B：“To increase or improve something to make it more successful”表示增加或改善某物以使其更成功，“boost”常见的释义就是“促进；推动；提高”，与该选项意思一致。
• 选项C：“To maintain something at the same level”是指将某物维持在同一水平，并非“boost”的意思。
• 选项D：“To completely eliminate something”意为完全消除某物，和“boost”的含义相差甚远。