单项选择题
A.≥20cm、≥10cm B.≥10cm、≥20cm C.≥20cm、≥20cm D.≥10cm、≥10cm
A.5~10 B.10~15 C.15~20 D.20~25
A.35%~65% B.35%~75% C.45%~75% D.45%~70%