三位同学用如图所示装置做一氧化碳还原氧化铁的实验．当观察到玻璃管A中的粉末由红棕色逐渐变为黑色时，停止加热，继续通一氧化碳，冷却到室温，停止通气，同时观察到澄清的石灰水变浑浊．

用一氧化碳还原氧化铁的实验装置

小明认为：依据上述实验现象可以判断出生成的黑色固体为金属铁．

小红认为：仅从上述实验现象，不足以证明生成的黑色固体为金属铁，她增加了一个实验：用磁铁靠近生成的黑色固体，看到有黑色固体被磁铁吸引．于是得出生成的黑色固体为金属铁的结论．

小光通过查询有关资料得知：

    During my second year of nursing school, our teacher gave us ____ test. I was a hard-working student and I did well in all the subjects. I ____(success) in finishing the questions until I read the last one, "What is the first name of the woman ____ cleans the school?"

    I saw the cleaning woman every day. She was short and about 60 years old. She had dark hair. But how should I know ____ name? I had never talked with her before. In ____, I had never thought about talking to her! I stared at my paper and started to feel rather guilty. At last, I finished my paper without ____(write) the answer to the last question.

    Before the class ended, one student asked the teacher whether the last question would ____(include) in our grade.

    "In your life," the teacher said," you will meet many people. All are important. They deserve your attention and care, even if all you do is just smiling and saying hello."

    I will ____ forget that test. Everyone deserves our attention and we should try ____(get) to know all the people who work and live around us. That was one of ____(important) lessons of my life. Later that day, I knew that the cleaning woman's name was Dorothy.

利用燃烧条件和灭火原理回答下列问题：

下列各句中，没有语病、表意明确的一项是（  ）