阅读下面短文，用括号内的所给的动词的适当形式填空，必要时可加助动词或情态动词。
Middle school life is coming to an end. Different students have different memories(记忆). Let’s take a look at two of the unforgettable memories.
Li Xiaohui, 15
My most unforgettable experience was the running for the PE test. When I   1  (run), I was too tired to go on. all my classmates came up to me and cheered me up. their encouragement helped me finish the run! I   2  never    2  (forget) it!
Gao Mingyi, 16
The most important one to me was my English teacher. Last year, when she   3   (know) I had given up an English-speaking contest, she told me, “any opportunity is important and you don’t know the result until you   4  (finish) it. Don’t give up easily.” Later on, I made my good use of every opportunity I had and achieved good results.