请问是否有"The X and Y" is singular, whereas "the X and the Y" is plural.
For example,
The CEO and chairman is in the office today.
Means: one person holding both the positions. Thus, this sentence warrents singular verb.
On the other hand,
The CEO and the chairman are in the office today.
Means: there are two people in the office. Therefore, this sentence
warrents plural verb.