题干

如图,已知△ABC为等边三角形,AB=2,点D为边AB上一点,过点D作DE∥AC,交BC于E点;过E点作EF⊥DE,交AB的延长线于F点.设AD=x,△DEF的面积为y,则能大致反映y与x函数关系的图象是(   )

A:

B:

C:

D:

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A

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    It is a popular Internet thing to focus on the upside of being in your 30s, and it is nice to know how to do basic modern-human-being things like paying your taxes and cooking a simple meal. But it can be a less-encouraging story at work: People in their late 20s to early 40s tend to report lower levels of job satisfaction and higher levels of emotional exhaustion than other age groups, according to new research.

    There's an obvious reason: These tend to be the ages when people have young children at home, and the researchers did find that this group reported feeling increasingly crunched for time. But adding to that pressure, coworker support also tends to decline at this age. Some researchers interpret the findings:

    Support from co-workers probably decreases in midlife as peers compete for limited resources(promotion bottlenecks are often encountered during this career stage. Also, whereas younger co-workers are often hungry to make up new social networks, and older workers seek identity-affirming work experiences in their remaining tenure(任期), mid lifers find it demanding enough just to maintain existing social networks. Meanwhile, time pressure likely increases as colleagues are all trying to enrich their own knowledge and experience.

    But the good news is that after about a decade of struggle, things start to pick back up again. Occupational psychologists say that happiness at work recovers when people reach their 40s, and that people in their 50s are more satisfied with their jobs than any other age group. Hang in there, 30-somethings-soon you will be older, but at least work will meet less frustration(挫折)!