游泳池长50米,小强每次都游9个来回,他每次游多少米?
50×9×2
=450×2,
=900(米).
答:他每次要游900米.
Success in life doesn’t happen_____. It’s the result of devoting yourself to what you’ve set out to do.
A.by design
B.by nature
C.by chance
D.on purpose
试论述艺术创作的主要心理因素。