The math textbook is about 22 ______ _ _ _, and the paper clip is about 28 _ _ _ _, weighing about 1 _ _ Xiaoming1min. You can take about 50 planes. _ _ _ _ _ Xiaoming weighs 38 _ _ _.
The math textbook is about 22 cm long, the paper clip is about 28 mm long and weighs about 1 g. Xiao Ming can walk about 50 meters in 0 minutes and weighs 38 kilograms. The mass of the plane is 9 tons and the speed of the car is 45 kilometers per hour. One cow weighs about 500 kilograms, and six such cows weigh about 3 tons. So the answer is: centimeters, millimeters, grams, meters, kilograms, tons, kilometers, kilograms, tons.