广谱抗菌药喹烯酮主要对动物的哪个系统的致病菌作用较强()
A.肠道致病菌
B.呼吸道致病菌
C.循环系统致病菌
D.生殖系统致病菌
E.神经系统致病菌
参考答案:A
Our research has focused on a drug which is so ______ as to be able to change brain chemistry.
A.powerful
B.influential
C.monstrous
D.vigorous
影响铁吸收的因素有哪些?