We'll take a cab to save time.

我们坐出租车，好节省时间。

With mathematical problems, you can save time by approximating.

对于数学题，你可以用近似法省时间。

Shopping online is a convenient alternative to driving to the store, because it helps save time.

网上购物相对于开车去商店来说是一个更便捷的选择，因为网上购物能节省时间。

I usually cut through the park to get to school, which helps me save time.

我通常抄近路穿过公园去上学，这样能省时间。

One person can save time and energy, thereby suitable for diagnosis and treatment of seroperitoneum.

一个人可以节省时间和精力，从而适合诊断和治疗腹腔积液。