wr grammar problem

Test Preparation SAT Preparation
1

<p>experts (agree that) permanently modifying eating and exercise habits rather than (merely dieting) for brief periods (are the key) (to controlling) weight.
a. agree that
b. merely dieting
c. are the key
d. to controlling
e. no error</p>

<p>Is "modifying eating and exercise habits" singular or plural? Explain.</p>

<p>Also, is it grammatical to say: X, Y, Z are the key to success.</p>

<p>What is the rule/ exceptions to a verb that is sandwiched between a singular noun and a plural noun (e.g. X,Y,Z are the "singular noun")
(I've seen this on CC, but can't find the thread)</p>

2

<p>Its singular - should be ‘is the key’
Parenthetical expressions are introduced by as well as, with, along with, together with, in addition to, no less than, rather than, like and similar phrases. Although they come between the subject and the verb, they do not interfere with the subject and the verbs agreement.</p>