it is后面加什么人称

　　It is not within my power to help you.

　　我是爱莫能助啊。

　　It is not clear what they want us to do.

　　我们不肯定他们要我们做什么。

　　It is quite possible that space and time are finite.

　　很有可能空间和时间是有限的。

　　It is important not to let things get out of perspective.

　　重要的是不要把事情轻重倒置。

　　It is difficult to find work in the present economic climate.

　　在目前这种经济大气候下很难找到工作。