正常人体内环境的理化特性经常保持状态
A．固定不变B．绝对平衡C．随机多变D．相对恒定
参考答案：D
蘑菇的孢子生长在菌褶的（ ）
A．菌盖上
B．菌柄上
C．菌丝上
D．菌托上
The Arabian Nights _____ well known all over the world, in which many a story _____ interesting and
instructive.[ ]
A. is; are
B. are; is
C. are; are
D. is; is
