单项选择题
A.叶缘 B.叶脉 C.叶肉 D.叶尖
A.(0.5~2.5)×1000000个/ml B.(0.5~2.0)×1000000个/ml C.(0.1~0.5)×1000000个/ml D.(2.0~2.5)×1000000个/ml
A.15~17℃ B.18~22℃ C.23~27℃ D.28~32℃