Questions

There is no difference except for the fact that the first one gives a hint that the function fun() is probably in another source file.

Alternative (a) refers to a delta

Partition is the word which is used for separation, dividing, mark off, etc... Compunding, union, attaching, total, etc... are antonyms of partition.

VPN's are implemented to provide a secure connection through public networks. A virtual private network extends a private network across a public network, and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network.

A mountain is what has roots that nobody sees, Is taller than trees, Up, up it goes, Yet it never grows.