Farmers can no longer keep constant watch over their flocks.

农场主已不再频繁看管他们的牧群。

The skull has a set volume, and the pressure inside of the skull is kept relatively constant.

颅骨内的容积是个定值，且压力保持相对恒定。

So do I always keep the weight constant? I don't have the weight go up or down?

那是一直保持同样的负重吗？不用增加或减少重量？

What we want to achive is a round link turn, which keeps my speed constant and in control.

我们想要的是一个连接处平滑的转弯，这样可以 保持滑行速度恒定，并使速度在自己的掌控中。

So what kind of things needs to be kept constant in the body?

那么什么样的东西需要在体内保持恒定呢？

He even arranged for sentries to keep constant watch on the entrance to the defile.

他甚至安排了哨兵， 时刻守望着隘口。

We even have buffers in our blood to keep our internal pH constant and ourselves healthy.

我们甚至在我们的血液中有缓冲剂来保持我们内部的 pH 值恒定和我们自己的健康。

You also need to keep the levels of sugar in the blood constant along with levels of ions and water.

您还需要保持血液中的糖含量以及离子和水的含量恒定。

Using mathematical models, researchers added an apple to the diet of every Brit over the age of 50—a total of 22 million adults—while keeping calorie intake constant.

研究人员们使用数学模型对2.2亿成年人中每位超过50岁英国公民的食谱中增加了一个苹果—并使他们每日摄取一定的热量。

During those isothermal processes, the temperature has to be kept constant while heat is transferred – which only works if the heat is transferred super slowly.

在这些等温过程中，温度必须在传递热量时保持恒定——只有当热量传递速度非常慢时才有效。