They work well, but they are slow and can't run for long.

它们动作很好，但是它们很慢并且跑的时间不长。

youdao

They work well, but they are slow and can ' t run for long.

它们运转得很好，但是它们很慢并且跑的时间不长。

youdao

Ten years ago, smooth plastic sleds became popular; they go faster than wooden sleds but are harder to steer and slow.

十年前，光滑的塑料雪橇开始流行起来；它们比木制雪橇跑得快，但是很难操控，也很慢。

youdao

Freight trains may be slow and inflexible, but they are capable of carrying huge loads.

ECONOMIST: A better way to fly

But the Wilson balls are quick and then they do slow down a lot so it does take a bit to get used to.

BBC: Laura Robson and Andy Murray

These steps add up to significant progress against cancer over time, but there is no denying that they are stubbornly and painfully slow.

FORBES: How We Can Pick Up The Pace In The Race To Cure Cancer