Xiao Qiang observed that steamed bread slices in summer are more prone to mildew than those in winter. He guessed that this was caused by the humid weather in summer, so he prepared two pies.

(1) The methods of scientific inquiry are: asking questions, assuming, designing experiments, analyzing data and drawing conclusions. According to the meaning of the question, it can be assumed that the steamed bread slices in summer are more moldy than those in winter because of the humid weather in summer;

(2) A controlled experiment refers to an experiment in which all the conditions are the same except one condition when studying the influence of one condition on the research object;

(3) Experimental variables, also called independent variables, refer to the factors or conditions manipulated by the experimenter in the experiment, and the only different variable in the controlled experiment of A and B is moisture.

So the answer is: (1) The steamed bread slices in summer are more prone to mildew than the steamed bread slices in winter because of the humid weather in summer (0.5 points)? (2) Control (0.5 points)

(3) Moisture (1)