为你解答.
6、I don't know how I should deal with the problem. （同义句）
I don't know (how to deal with) the problem.
我不知道如何处理这个问题.
7、When we face the danger, we should be brave. （同义句）
If we face the danger, we should be brave.
如果要面对危险,我们应该勇敢.
8、Lucy learns Chinese （by watching Chinese language videos）. （提问括号部分）
How does Lucy learn Chinese?
Lucy如何学中文?