Найдите подлежащее в предложении по английскому языку. Only 40 per cent of the last year's supply of potatoes reached

Only 40 per cent of the last year\'s supply of potatoes reached the storages. — Только 40 процентов прошлогодних запасов картофеля поступило на склад.

Reached — is the predicate of this sentence. This sentence is in Past Indefinite. Past Indefinite is formed with the help of the suffix – ed or we use the second form of irregular verbs. The auxiliary verb of Past Indefinite is to do. We use the second form — did.

 Negative.

Only 40 per cent of the last year\'s supply of potatoes didn\'t reach the storages.

Interrogative.

Did only 40 per cent of the last year\'s supply of potatoes reach the storages?