题干
阅读理解，根据短文选择正确答案
It was Saturday yesterday. It rained. We were at home. My mother phoned grandma. Then she washed clothes. My father cooked some noodles and vegetables for lunch. My brother Sam didn't help him. He watched TV. But I helped Dad. I think it will be sunny tomorrow. We will have a picnic in a park. And we will be very happy.
．如上所示，明文“4”通过加密加密后得到“3”再发送，接受方通过解密钥解密得明文“4”，问若接受方接到密文为“4”，则解密后得明文是