5.3. the problems and obstacles. 1. certain types of substances derived from nature are only in season. 2. the substance peroxide Jane if there is hydraulic concentration too dangerous to try out. It is used in an appropriate quantity. 3. the equipment used in the experiment, only that the General could not be found. 4. hydro peroxide compounds and Jane if sunlight will break into water and oxygen gas at once may cause some changes to the properties.
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