把管内的氢氧化钠残液倒入水中，你就会发现：溶液会使红色石蕊试纸变蓝。

Turn the remnant of sodium hydroxide in the tube into water, and you'll find the solution turns red litmus blue.

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把管内的氢氧化钠残液倒入水中，你就会发现：溶液会使红色石蕊试纸变蓝。

Turn the remnant of sodium hydroxide in the tube into water, and you'll find the solution turns red litmus blue.

youdao