Two of these were extensions of that system, to Downtown Brooklyn and Van Cortlandt Park, but the other two - the Centre Street Loop Subway (or Brooklyn Loop Subway) and Fourth Avenue Subway (in Brooklyn) - were separate lines for which construction had not progressed as far.
Но другие две — Centre Street Loop Subway (или Brooklyn Loop Subway) и линия Четвёртой авеню — были отдельными линиями.