be sure about

确信中释

1 That is scary, and we cannot be sure about changes in the future..这是可怕的，因为我们无法确定未来会发生什么变化。

2 There were many I didn't know, and others I couldn't be sure about because they were all covered in green parasites..这里有许多我不认识的树，还有有一些树我没法确认，因为它们都覆盖在了密密麻麻的绿色藤蔓植物下。

3 However, you need to be sure about no reuse..但是，需要确保没有重用。