A:注射激素抑制抗体产生
B:注射神经递质提高传递效率
C:注射受体蛋白增加受体数量
D:注射淋巴因子增强免疫能力
溶质
NaF
Na2CO3
NaClO
NaHCO3
pH
7.5
11.6
9.7
8.3
下列有关说法正确的是( )
从方框中选择正确的词,补全句子。
closed, fly , share , sheep, popular
(1) I often see some children____ kites in the park at weekend.
(2)Yao Ming is ____ with young people.(3)We____the world with plants and animals.(4)The bookshop is ____ at this time everyday.(5)My uncle keeps many____ on his farm.
通过对郑氏始孔子鸟化石的研究,推断鸟类可能由古代的哪类动物进化而来( )
设常数λ>0,a>0,函数f(x)=x2λ+x﹣alnx.
(1)当a=34λ时,若f(x)最小值为0,求λ的值;
(2)对任意给定的正实数λ,a,证明:存在实数x0,当x>x0时,f(x)>0.