光明中心小学把老式水龙头改成节水型龙头后,每个星期比以前节约用水2吨,平均每天节约用水几分之几吨?
2÷7=27(吨).
答:平均每天节约用水27吨.
I'm afraid you can't mend it. Please go and have your uncle _____. [ ]
A. to do it
B. done
C. done it
D. do it
醛固酮的主要功能是()
A.排泄代谢废物
B.调节激素分泌
C.调节水平衡
D.调节酸碱平衡
E.调节电解质平衡