Which of the following is true about the origins of baseball

A．Historians agree that baseball was invented by Abner Doubleday.

B．Baseball, as played in the early 19th century, differed very little from today's game.

C．As early as the 1700s, English boys played a game called "baseball".

D．The first standard set of baseball rules was established at the turn of the century.

以下首次申报的国产涉水产品需由省级卫生监督机构进行生产卫生条件审核，再报卫生部审批的是（）。

A.防护材料

B.混凝剂

C.管材管件

D.与饮用水接触的联接止水材料