Boost vs heighten vs lift

[Monica]

In the following multiple-choice exercise:
The mailing list has done much to ... the numbers of people attending.
A lift B encourage C heighten D boost
I know the correct answer is "boost" but I was wondering what makes "lift" and "heighten" incorrect, as they also mean "increase". Thank you

[Alan]

Hi Monica,

Certain words go well together and have associations known as collocations. The verbs 'lift' and 'heighten' also have their ideal partners when used in a figurative way. 'Lift' is often associated with words like 'hopes' 'spirits' and 'heighten' would be used with words like 'expectation' 'concentration'.

Alan
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