引起肾脏1α-羟化酶活性增加的原因是()
A.PTH浓度升高
B.血钙浓度降低
C.降钙素浓度降低
D.血磷浓度升高
E.1,25(OH)2D3浓度升高
参考答案:A, B, C
This will be a year of action, and that action should begin by extending unemployment insurance for Americans who were _______ in the economic slowdown.
A.laid out
B.laid off
C.laid on
D.laid down
下钻至东营组以下地层遇阻,划眼应注意哪些事项?