题目

阅读短文，从方框中选择适当的词并用其正确形式填空，使短文通顺、意思完整。请将答案写在下面题号后的横线上。每空限填一词，每词限用一次。方框中有两个词是多余的。 never, little, one, usually, dentist, healthy, full, than, program, together, work, writernever, little, one, usually, dentist, healthy, full, than, program, together, work, writerMy work is kind of special（特别）. I work from Monday to Thursday and I work at night. So in the daytime, I often sleep for at【1】7 hours. Then I get up, have some food and watc17．${\;}_{15}^{52}$P可以用于脑恶性肿瘤的放射治疗．下列关于${\;}_{15}^{52}$P的叙述中正确的是（　　）A．${\;}_{15}^{52}$P的原子核中含有15个中子B．${\;}_{15}^{52}$P的相对原子质量为32C．${\;}_{15}^{52}$P原子的质量数是17D．${\;}_{15}^{52}$P原子中含有的电子数和质子数都是15