What should be checked first while reading a rainfall map?

Correct answer: Legend

The direct answer is A: check the legend first. A rainfall map uses colours, lines, symbols, or shades to represent different rainfall ranges. The legend, also called the key, tells us what each colour or symbol means. Without reading it, a student may confuse a dark shade with high rainfall or interpret the map backwards. The correct method is: first read the legend, then identify the place, match its colour or symbol with the legend, and finally state the rainfall category or compare it with another place. Option A is correct because it provides the map’s decoding instructions. Option B is wrong because the colour of the paper has no geographical meaning. Option C is wrong because the physical size of the picture does not tell us the rainfall amount. Option D is wrong because a page number only locates the map in a book and gives no climate information. The legend is therefore the first and most necessary check. Exam cue: never interpret a thematic map before reading its key, scale, and labels; for this question, the key is the first item.