I'm just making sure the gun stays handy in case Tyler's completely lost it.我要把枪随身带着以防泰勒彻底失控

make sure设法确保

I'll go with her to make sure she comes to no harm.

我要和她同去以免她受到伤害。

I'll make sure of the time of the flight.

我要核实一下这班飞机的时间。

in case万一，以防；如果

In case of flood, the dam can protect us.

在发洪水的时候，大堤可以保护我们。

Write the telephone number down in case you forget.

把电话号码写下来以免忘了。

Yeah, a bit of a wild-goose chase,是的，有点白费周折

a bit of一点儿的

Setting up this business was a bit of a gamble.

开办这样的公司有点冒险。

The party was a bit of a damp squib.

这次聚会有些扫兴。