Questions

Giraffe have no vocal cords.

"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.

Black  surfaces are good emitters of heat ( They are also good absorbers of heat). If the black surface is rough too, the emitting will be better. So (b) is the correct answer. Shining surfaces reflect back radiation. So if the black surface is also shining the effectiveness of emitting heat is lessened.

The size of gear is usually specified by pitch circle diameter.

The alphabet 'B' resembles same as a fly 'Bee' in pronouncing.