(a) Keep all property useful and necessary in its business in good working order and condition in all material respects, ordinary wear and tear excepted and (b) maintain with financially sound and reputable insurance companies insurance on all its property in at least such amounts and against at least such risks (but including in any event public liability, product liability and business interruption) as are usually insured against in the same general area by companies engaged in the same or a similar business or having similar properties similarly situated.