Sentence improvement — Correct the subject–verb agreement and unit style: ‘‘20 kms are not a great distance in these days of fast moving vehicles.’’ Choose the best improvement that makes the measurement singular and idiomatic for modern English usage.

Given sentence
20 kms are not a great distance in these days of fast moving vehicles.

Concept/Approach
A measure or amount used as a single extent is treated as a singular subject (‘‘Twenty kilometres is...’’). Also, the standard unit style is ‘‘km’’ (not ‘‘kms’’), and the compound modifier ‘‘fast-moving’’ takes a hyphen when it precedes a noun.

Option analysis
A: is not a great distance — Correct singular verb with a measure of distance: ‘‘20 km is not a great distance...’’B: is no distance — Overstates the idea (zero distance) and alters meaning.C: aren't a great distance — Plural verb ‘‘aren't’’ is ungrammatical with a measure treated as a single quantity.D: No improvement — Leaves the agreement error and nonstandard unit form.

Common pitfalls
Confusing plural-looking nouns (‘‘20 km’’) with plural agreement; in grammar, quantified measures typically take singular verbs.

Final Answer
is not a great distance