在空格处填入合适的词完成这封信。 Hi, Lisa, I can't wait to tell you this! I went to the Great Wall today! It is amazing! The Great Wall is about 2, 000 years old and it _____________ about 6, 000 kilometres long! I was really excited and _____________ many pictures. I _____________ show you later. And guess what? I _____________ by train! I met a girl, Lina, on the train. We talked all the way to the Great Wall. She told me something about the railway. It is one of China's earliest railways! Isn't that interesting? Yours, Lydia