Questions

The Dibang Wildlife Sanctuary is one of the eight wildlife sanctuaries of Arunachal Pradesh, India.

The seven elements — helium, neon, argon, krypton, xenon, radon, and oganesson of Group 18 of the periodic table are Noble or Inert gases.

Radon is the heaviest and Helium is the lightest gases of the noble gases.

Envelope is a letter holder for one letter and in the question it mean that it holds one letter. Eye is also a word which starts and end with E but has one letter in the middle.

Resident set is that portion of the process image that is actually in real-memory at a particular instant. Working set is that subset of resident set that is actually needed for execution. (Relate this to the variable-window size method for swapping techniques.)

Facilitate means assist someone in their progress or work. Here Help is the only word which is similar in meaning with facilitate. Halt and check are antonyms i.e opposite in meaning of facilitate. 

Hence, facilitate is similar in meaning to help.