In the following passage, some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives. Technical skill ____________ to the ability and knowledge to use the pedagogy, tools and techniques involved in the teaching and research of a specific subject. Ability in programming or software designing and operating a computer is, ___________ instance, a technical skill. There are two things a teacher should understand __________ transformational technical skills. In the first place, he must know __________ skill and what level of skill should be applied on a particular student. He should be ____________ enough with their potential to ask discerning questions. Secondly, a teacher must understand the role of each event organised and the transformational skill applied, and the inter relationships between the events and skills. He should be ____________ enough with their.

Introduction / Context:
This cloze question examines your understanding of adjective use and collocations in English. The sentence describes a teacher who needs to understand the potential of students well enough to ask discerning questions. You must select the word that completes the phrase He should be ____________ enough with their potential in a grammatically correct and natural way.

Given Data / Assumptions:
The structure given is He should be blank enough with their potential to ask discerning questions. The verb be is followed by a complement that must be an adjective to describe the state of the teacher. Enough indicates degree of that quality, and the preposition with links the adjective to the noun potential.

Concept / Approach:
In English, the common adjective used with enough and with in this context is familiar, as in be familiar enough with a subject. The phrase be familiar with something means to have sufficient knowledge or experience of it. The words familiarly, familiarness, and familiarity are related but have different grammatical roles, and acquainted requires a different preposition pattern. Therefore, familiar is the most appropriate choice.

Step-by-Step Solution:
Step 1: Identify that the complement after be should be an adjective describing the teacher.Step 2: Recognise that the pattern be familiar with something is standard English for having knowledge of it.Step 3: Combine familiar with enough to mirror common phrases like sufficiently familiar with.Step 4: Insert familiar in the blank to produce He should be familiar enough with their potential to ask discerning questions.Step 5: Confirm that the sentence now reads smoothly and conveys the intended idea.

Verification / Alternative check:
Test each alternative. Familiarly is an adverb and cannot directly follow be in this position. Familiarness is a rarely used noun form and does not fit after be with enough. Familiarity is also a noun, so be familiarity enough with sounds wrong. Acquainted is an adjective but the usual pattern is acquainted with, and the phrase acquainted enough with their potential would be less natural in this pedagogical context than familiar enough with their potential. The passage also uses familiar earlier as the most straightforward word for knowing a subject well.

Why Other Options Are Wrong:
familiarly cannot serve as a subject complement; it modifies verbs, not subjects. familiarness is not standard modern usage and would disrupt the flow of the sentence. familiarity would require a different construction such as his familiarity with their potential, not be familiarity enough. acquainted shifts the nuance slightly and is less commonly combined with enough in this structure; moreover, the standard exam collocation emphasises familiar enough with as the ideal expression for adequate knowledge.

Common Pitfalls:
Students sometimes choose familiarity because they associate it strongly with knowledge, but they ignore the grammar of the be verb plus complement. Others may be tempted by acquainted because it also takes with, without noticing that the phrase familiar enough with is far more frequent. Always check the part of speech and typical collocations when answering cloze questions.

Final Answer:
The correct word for the blank is familiar, giving He should be familiar enough with their potential to ask discerning questions.