•The road was blocked for two hours after the accident, but traffic is now flowing smoothly again.事故发生后，这条路堵塞了两个小时，不过现在交通又恢复畅通了。

•Lead is added to fuel to make car engines run more smoothly.燃油中加入了铅，以使汽车引擎运转更流畅。

•The pregnancy's gone very smoothly so far.迄今为止，怀孕以来一切正常。