Explanation:

The correct collocation is ‘suspicious of’ when referring to people: ‘He is suspicious of all his neighbours.’ ‘From’ indicates origin and does not collocate with ‘suspicious.’ ‘Before’ relates to time or position and is incorrect here. ‘None of the above’ is therefore wrong. Note: ‘suspicious about’ can be used for situations, but with a person we use ‘of.’

Explanation:

Crowd names a group of people considered as a single unit, which makes it a collective noun. The sentence uses the singular verb ‘was’, reinforcing that the group is treated as one entity. It is not a proper noun (no specific name) nor an abstract noun (not an idea or quality). While collective nouns fall under common nouns, the precise classification here is collective.

Explanation:

The active sentence is in the present perfect: ‘has cut’. The passive for present perfect is: Object + has/have + been + past participle (+ by + agent). Moving ‘all the salaries’ (plural) to the subject position gives: ‘All the salaries have been cut by the company.’
Why others are incorrect:
– Option 2 changes the tense/aspect to simple present (‘are cut’).
– Options 3 and 4 introduce the modal ‘should’, altering meaning and tense; Option 4 also drops ‘All the’.

Explanation:

Nefarious means wicked, evil, or morally reprehensible—especially describing actions (e.g., a nefarious scheme). It comes from Latin ‘nefarius’ (wrong, criminal). Therefore, ‘Morally bad’ is correct.
Elimination:
– Option 1 (Honest): Antonym of nefarious.
– Option 3 (Extremely wealthy): Relates to affluence, not morality.
– Option 4 (Very fearful): Describes emotion, not moral character.
Synonyms: wicked, villainous, heinous, depraved.

Explanation:

The fixed idiom is “cry over spilt/spilled milk,” meaning to lament something that cannot be changed. Hence, the correct preposition is “over.” The other options do not form the idiom: “cry on” is used only in phrases like “cry on someone’s shoulder,” “cry at” is used with events (e.g., cry at a movie), and “cry upon” is archaic and not idiomatic here. Note: the standard form is spilt/spilled milk, not split milk.

Explanation:

Subject-verb agreement: ‘Either of + plural noun’ takes a singular verb because ‘either’ refers to one of the two. Since ‘good’ is an adjective, the correct linking verb is ‘is.’
– ‘are’ (plural) is incorrect.
– ‘have’ and ‘has’ require an object (e.g., ‘has good quality’) and do not link to an adjective directly.
Therefore: ‘Either of these two pens is good.’

Explanation:

The correct spelling is ‘reservoir’ (R-E-S-E-R-V-O-I-R), meaning a storage place for liquid and derived from French ‘réservoir’. The other options are misspellings: ‘Reservoure’ incorrectly uses ‘ou’ and adds a final ‘e’; ‘Reservor’ omits the ‘i’; ‘Reservour’ uses ‘ou’ instead of ‘oi’. Hence, Option 1 is correct.

Explanation:

Ephemeral means lasting for a very short time; transitory or short‑lived (synonyms: fleeting, transient, momentary). Etymology: from Greek ‘ephemeros’ meaning ‘lasting only a day’. Example: ephemeral trends or the short adult life of a mayfly.
Elimination of options:
– Option 1 (Permanent): Opposite of ephemeral.
– Option 2 (Mysterious): Relates to enigma, not duration.
– Option 4 (Loud): Pertains to sound, not time.
Hence, Option 3 (Temporary) is correct.

Explanation:

The natural preposition to express that an action happened within a period of time is “during.” Hence: “She wrote this article during her holiday.”

Why others are less suitable:
– in: Not idiomatic with singular “holiday” for time. We say “in the holidays” (plural) or “in the holiday season,” but not “in her holiday.”
– on: Common with days/dates (on Monday) or in the fixed phrase “on holiday” (meaning away), but “on her holiday” is awkward for marking time and can be misread as topic (an article on/about her holiday).
– by: Indicates a deadline (no later than), which does not fit the intended meaning.

Explanation:

Passive: They were seen to go out. With verbs of perception (see/hear), the passive pattern is be + past participle + to-infinitive, which corresponds in the active to: Subject + saw + object + bare infinitive (without to). The object is them (from they). Since the passive does not specify the agent, the standard neutral active uses a general agent like we/people. Hence: We saw them go out. Option 2 remains passive; Options 1 and 3 are grammatically possible actives but introduce specific agents not indicated by the original. The conventional active equivalent is Option 4.