Questions

The meanings of the given words are as follows:
Zealous: having or showing zeal
Droopy: hanging down limply
Gigantic: of very great size or extent; huge or enormous
Tenacity: the quality or fact of being able to grip something firmly; grip
Assiduity: constant or close attention to what one is doing
Fervent: having or displaying a passionate intensity
Apathetic: showing or feeling no interest, enthusiasm, or concern
Conceited: excessively proud of oneself; vain
Capacious: having a lot of space inside; roomy
Hilarity: extreme amusement, especiallywhen expressed by laughter
Livid: furiously angry
Therefore, it can be observed that option C i.e. ‘fervent, apathetic’ forms a synonym- antonym pair of ‘zealous’.

In Europe, Fohn winds are prevalent in Swiss Valleys

The Quality Factor is also defined, as Q. So it is a number, which reflects the lossness of a circuit. higher the Q, the lower are the losses.

the quality factor is measurement of efficiency (or effectiveness) of a device or circuitry. In literal sense quality factor means qualitative performance of a device.

A Coffin.

Deficiency of Iodine cause Goiter also called Enlarged Thyroid. It doesn't give any pain but difficult to swallow and breath are its causes.