【初中·完形填空·A Rainy Morning】
阅读下面短文，从各题所给的四个选项中选出可以填入空白处的最佳选项。

I woke up late. The sky was grey and rain beat against the window. I had a maths test that morning, and I had left my calculator at school.
I ran to the bus stop without breakfast. The bus was late. When it finally came, it was so crowded that I could hardly get on. I felt my heart sink.
At school, my deskmate Lisa saw my face. "You look worried," she said. I told her about the calculator. She put hers into my hand and said, "Take it. I can borrow one."
I passed the test. But I remember more clearly that a small ______ can change a whole morning.

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