题目

小亮解方程组 的解为 ，由于不小心，滴上了两滴墨水，刚好遮住了两个数●和★，请你帮他找回●这个数，●＝． 答案：【1】4 Great attention must be paid ____ welfare, especially in the poor area.   A. develop      B. to develop      C. to developing      D. developing