The car ____ (to wash) every month.

The task is to choose the correct form of the verb to complete the sentence.

The sentence is in the present simple tense, and it describes a habitual action that happens every month. The subject is "The car", which is singular.

The sentence is in the passive voice because the car is being washed, it does not wash itself.

To form the present simple passive, we use the structure: subject + am/is/are + past participle.

Since the subject "The car" is singular, we use "is". The past participle of "wash" is "washed".

Therefore, the correct form is "is washed".

Let's look at the options:

• are washed: Incorrect because the subject is singular.
• is washed: Correct because the subject is singular and the verb is in the passive voice.
• washed: Incorrect because it would imply a past simple active or passive, and the context requires present simple for a habitual action.
• is wash: Incorrect because "wash" is the base form of the verb, not the past participle needed for the passive voice.

Ответ: is washed