Multiple choice

The upper branches of the tallest trees produce more leaves ___ other branches.

  1. than do

  2. than they do

  3. than does

  4. than it does

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The comparison requires a verb that matches the subject 'other branches' (plural). 'Than do' is the correct elliptical construction to avoid repeating the verb 'produce'.