Good responses were given by many candidates.  Few fumbled due to their failure to relate cohesion and adhesion forces with molecules of mercury and glass.

The expected answers are:

Mercury does not wet glass because (force of) cohesion/attraction of mercury molecules is greater than (force of) adhesion/attraction between glass and mercury molecules.

Water wets glass because (force of) adhesion/attraction between glass and water molecules is greater than (force of) cohesion/attraction of water molecules.