Section 81B. The board may approve, for the purposes of sections seventy-four, seventy-four A or seventy-six A, any school for nurses or for practical nurses, as the case may be, in another state or country which maintains standards substantially the same as those required for an approved school in this commonwealth, and which, in the case of a school in another state, is approved by the board for nurses or for practical nurses, or corresponding body, of the state in which the school is situated.