As a result, all the ________ of fish that had gradually disappeared from the Thames since 1800 have returned. Some are even caught by fishermen outside the Houses of Parliament.
句意：结果，自1800年以来，所有从泰晤士河上消失的鱼类都回来了，有些甚至被议会大厦外的渔民捕获。species物种；种类。kind和sort都表示物品的种类。form形式，形状。故选D。