“Essential” is an adjective that is used to talk about something that is necessary. This adjective could come up in any part of the exam, and candidates should be able to easily use it in in the writing and speaking paper.
Examiner: “How to you think the government can help reduce pollution?”
Candidate: “Well, I think it is essential that they encourage businesses to be more environmentally friendly”
A clear day without wind or rain is (4)…… in order to be able to do a parachute jump.