しきりに (translations)→ bitterly busily conjecture copiously desperately eagerly earnestly endlessly fluently frequently furiously hard imperiously incessantly insistently intently keep much often steadfastly terribly urge urgent urgently variously
てきぱきと (translations)→ brisk briskly expertly fast promptly promptness quickly sharp
みるみるうちに (translations)→ immediately increasingly
スピード (translations)→ speed velocity
急速に (translations)→ dramatically suddenly