This question tests your understanding of subject-verb agreement and verb tenses in English grammar. The blank (118) requires the correct verb form to complete the sentence.

The key to solving this is to identify the subject of the verb. The subject is "the keys", which is a plural noun. Therefore, the verb must agree with this plural subject.

Let's analyze the options:

• were found: This is a plural verb in the simple past tense. It correctly agrees with the plural subject "the keys".
• found: This is the simple past tense form, but it is used for a singular subject (e.g., "He found the keys"). It does not agree with our plural subject.
• find: This is the base form (plural present tense or infinitive). It is not appropriate for a statement about a past event.
• finds: This is the present tense form for a singular subject (e.g., "He finds the keys"). It does not agree with our plural subject.

The most suitable option is were found because it provides the correct plural past tense form to match the subject "the keys".

Related Concepts & Formulae

Subject-Verb Agreement: A fundamental rule in English grammar is that a verb must agree in number with its subject. If the subject is singular, the verb must be singular. If the subject is plural, the verb must be plural.

Formula: Singular Subject + Singular Verb | Plural Subject + Plural Verb

Simple Past Tense: This tense is used to describe an action that was completed in the past. For the verb "to be", the past tense forms are "was" (singular) and "were" (plural).