on condition that 雅思

He can use the bicycle on condition (that) he returns it tomorrow.

自行车给他, 条件是明天必须归还。

On condition that the front body shape of the projectile is unchangeable,a formula is obtained for determining the relation between the optimum boattail angle and the supersonic flight region.

在丸前体外形和外界大气密度不变的条件下，提出了利用丸炮口马赫数和顶点马赫数确定旋转丸最佳尾锥角的方法。