"The beauty of Lake Taihu is in the water". It is reported that there are nearly a hundred catering boats on Lake Taihu. In order to check whether the wastewater discharged by these boats meets the standard, please (1) solids is a way to remove insoluble solids, so remove solid impurities in the wastewater with the method of filtration; filtration of glass instruments used beakers, funnels, glass rods;

The answer is: filtration; glass rods, funnels;

(2) determination of acidity and alkalinity of the solution can be used to pH test paper;

The answer is: pH test paper;

(3) ② control the total number of food and beverage vessels and ④ domestic sewage and industrial wastewater treatment and discharge can reduce the pollution of the water body, thereby protecting the ecological environment of Lake Taihu; ① ban on stocking fish and shrimp is not conducive to the protection of the ecological environment of Lake Taihu, ③ large number of construction of hotels and restaurants in the lake area, it will increase the discharge of domestic sewage and other substances into the lake, is not conducive to the protection of the ecological environment of the Lake Taihu;

Therefore, choose ② ④.

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