1, (1) because 2kg = 2000g, 3000 >; > 300 & gt200 in 2000, so 3000 g >; 2 kg > 300 g > 200 g. So pumpkin >; Chinese cabbage > tomato > apple. (2) 1000÷200=5 (pieces) A: Five apples just weigh 1 kg. (3) Other mathematical questions that can be asked are: How much is a pumpkin heavier than an apple? A pumpkin weighs 2800 grams more than an apple. When comparing the same numbers of two units, you can directly compare the numbers before the units, and the bigger the numbers, the more; If the units are different, the units must be unified before comparison.