4公顷50平方米=______平方米.
4公顷50平方米=40050平方米.
故答案为:40050.
You should follow _____ of the medicine, and take three pills every day.
A.direction
B.explanations
C.instructions
D.methods
引导接车时,列车以不超过20km/h速度进站,并做好()的准备。