题目

Every day this happens _______ me in the school library.              A. to             B. in               C. on               D. with 答案：A科学家发现，亚硒酸钠（Na2SeO3）能消除加速人体衰老的活性氧．亚硒酸钠中硒元素（Se）的化合价为（ ）A．+1B．+2C．+3D．+4