Questions

"The moon smiled at me" is the example of personification in the given options.

Personification is a technique in which we give objects human traits like emotions, gestures, speech,... by using metaphor. 

Here moon is an object which cannot smile but using metaphor sense, we gave that sense to it.

Echolocation is an adaptation bats use to hunt insects in flight, locate flowering plants and find warm places for hibernation.

Indian business magnate Mukesh Ambani topples Jack Ma as Asia’s richest person as he positions Reliance Industries to disrupt the e-commerce space in India.

The chairman of India’s refining-to-telecoms conglomerate, Ambani was estimated to be worth US$44.3 billion in July 2018 with the share price of Reliance Industries rising 1.6 per cent to a record 1,099.8 rupees (US$16.05), according to Bloomberg Billionaires Index.

Jack Ma’s wealth stood at US$44 billion at the close of trading on the sameday in the US, where the company is listed.

I am black gold i.e charcoal. It is black when it is not used and when using it is red due to fire and when used it is in grey color as it becomes ash. 

without this centripetal force, circular motion is not possible. It acts radially towards the centre and if this force is removed there will be no circular motion but the revolving body will fly off at a tangent.