Also, because the environment during which the deposits formed is not well understood, scientists are not sure how diverse they will be.

这些沉积物的形成环境现在还没有被完全弄清楚，科学家们不确定它们之间是否有差异。

youdao

We not only pack them carefully to make sure they are strong enough for a sea voyage and rough handling, we also mark each case with warning signs such as FRAGILE, KEEP DRY, DON't USE HOOK, etc.

我们不仅认真包装货物，确保包装结实能承受海洋运输和野蛮装卸，而且每个包装上标出了“小心易碎”“保持干燥”“禁用手钩”等详细的警示标志。

youdao

Also not sure if I'm really behind but I just came across digital photo frames and being the gadget junky that I am, I think they are pretty awesome.

我不敢肯定我是不是很落后，我刚刚才接触数码相框和其他一些小玩意，我觉得它们太强大了。

youdao

They are also advised not to give anti-reflux medicines for hoarseness unless they are sure patients need them.

VOA: special.2009.09.02

We should also agree that all gun sellers should check to make sure they are not arming criminals.

CNN: Commentary: Stop flow of U.S. guns to Mexico drug war