(2) Put a piece of clean paper with the same size on each of the two trays in operation A to prevent drugs from corroding the trays.

(3) To measure 10mL water, a measuring cylinder with 10mL specification should be selected; When adding liquid to the measuring cylinder, the liquid should be added to the scale line by pouring, and then added to the scale line by using the rubber dropper. The glass instruments used are 10mL measuring cylinder and rubber-tipped dropper.

(4) In order to prevent impurities from entering the filtrate without filtration, resulting in turbidity of the filtrate, the liquid level poured during filtration should be lower than the edge of the filter paper.

So the answer is: (1) iron platform; (2) preventing drugs from corroding the tray; (3) Rubber pointed dropper; (4)C。