如图,在△ABC中,∠C=90°,BD平分∠ABC交AC于D,DE是AB的垂直平分线,若AD=3,则AC等于( )
﹣ The novel seems a little boring.
﹣You won't enjoy it you put your heart into it.
α-银环蛇毒能与突触后膜上的乙酰胆碱受体牢固结合;有机磷农药能抑制乙酰胆碱酯酶的活性,而乙酰胆碱酯酶的作用是清除与突触后膜上受体结合的乙酰胆碱。因此,α-银环蛇毒与有机磷农药中毒的症状分别是 ( )