某商场经销一种成本为每千克40元的水产品，经市场分析，若按每千克50元销售，一个月能售出500千克；销售单价每涨价1元，月销售量就减少10千克．针对这种水产品的销售情况，请解答以下问题。

(1)当销售单价定为每千克55元，计算月销售量和月销售利润；

(2)商场计划在月销售成本不超过10000元的情况下，使得月销售利润达到8000元，销售单价应定为多少?

When you stop and think about your high school or college alma mater, were your experiences more positive or negative Do your feelings of (1) in that school have anything to do with whether or not your school was single-sex or coed (2) to send their children to single-sex schools, because they feel both (3) when they study in the company of students of the same sex. They (4) .
For years, only parents who could afford to send their children to private schools, or who had (5) , chose single-sex education for their children. Single-sex schooling was (6) for most American families. Today, however, along with (7) , public schools are experimenting with the idea of (8) .
Girls may be the ones who benefit most from single-sex schooling. Studies have shown that (9) in coed classrooms because teachers sometimes pay more attention to boys. Girls’ (10) toward their studies tends to disappear as they begin to feel less successful. They start to (11) outperform them in math and science. As boys (12) , girls start to lose it. Moreover, adolescence is (13) for girls. As they experience adolescent changes, some girls become depressed, develop an addiction, or suffer from (14) .
In the early 1990s, some influential people said that being in single-sex classes could (15) . Schools across the country began creating single-sex classrooms and schools. But many critics claim that (16) may actually be detrimental to a girl’s education because they (17) of sex differences.
The renewed interest in single-sex schooling (18) among Americans. Those who give it full endorsement believe girls need an all-female environment to take risks and find their own voices. Those who (19) of single-sex schooling wonder whether students’ lack of achievement warrants returning to an educational system that divides the sexes. They believe there is no (20) .