It is very hard to demonstrate causes using non-experimental data such as this.

很难用这样的非实验数据来论证原因。

youdao

However, it is very hard to demonstrate causes using non-experimental data such as this.

然而，使用诸如此类的非实验数据来证明原因是非常困难的。

youdao

However, it is very hard to demonstrate causes using non-experimental data such as this.

然而，使用诸如此类的非实验数据来证明原因是非常困难的。

youdao