Questions

Sound waves cannot be transmitted through vacuum. 

The President and Vice-President of United Arab Emirates Sheik Mohamed bin Zayed Al Nahyan and Shaik Mohammed bin Rashid Al Maktoum announced in Febraury 2017 that they are planning to build the first inhabitable human settlement on Mars by 2117.

This is for the first time that no Literature Prize will be given in 70 years because of a #MeToo scandal.

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

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’.