Hello, class. I always feel sad to see someone asking for answers online instead of solving problems and ideas. The convenience of the internet has trained too many lazy students, which is of no help to learning. In the long run, it will inevitably have a negative impact on the results. I suggest you think more first. If you can't, don't ask the answer directly. If you think about it, you will get it, and it is unacceptable to take it.