上挂钩

Materials And Methods 1, The animal model of Sprague-Dawley rat for maxillary protraction was made in this study, and an appliance based on the principle of protraction headgear was designed and made for maxillary protraction treatment which was hooked over the front of the zygomatic arch ,and a hole was made on the skull in the experimental group rat .

以面具式前牵引矫治器为原理制作特殊的前牵引支架，以外科方法安装支架挂在大鼠颧弓前端，在实验加力组大鼠头颅上打孔，安放挂钩，通过弹性牵引提供支架向前牵引的支抗。2、以该动物模型为基础，选用90只五周龄的Sprague—Dawley健康雌性大鼠作实验动物，随机分到实验加力组、正常对照组、手术对照组。

Hook of Holland 荷兰钩 He hung his coat on the hook behind the door.

他把外套挂在门后的挂钩上。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。