[micaelo]

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

[English-coach]

Hello...

You are correct, all of these words are very similar in meaning but in this case, we boost numbers. (Try to think of it as a fixed expression).

As for the other words...

Lift is a more physical action. Like to lift my arm or to lift a sofa.

Highten refers to increasing the hight of something, also in a physical way. If you use it without an object as well (eg...the tension heightened as more people entered the room).

I hope that helps!
Diana