题干

如图,画出反射光线,标出反射角.

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解:先过入射点垂直平面镜作出法线,再根据反射角等于入射角在法线的右侧画出反射光线,入射光线与平面镜的夹角为40°,所以入射角为90°﹣40°=50°,故反射角也为50°.

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    Lisa Pina never thought she would need the fire safety training she received during her apprenticeship(学徒期)as a union painter and dry waller(筑墙工). On Friday morning, she was thanking God she had it.

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