B
生物医药大词典
by MedSci
菜单
词典
分类
百科
诗词
背单词
英文名
DeepEvidence ↗
确认登录状态…
例句 /
Correct posture and facing must be maintained at all times.
Correct posture and facing must be maintained at all times.
第二，要随时保持正确的姿势和方向。