题干

甜菜块根细胞的液泡中有花青素,使块根表现为红色,将块根切成小块放在蒸馏水中,水无明显颜色变化,但用盐酸处理这些块根后,则能使水变红,这是因为(    )

A:细胞壁被盐酸解离

B:盐酸破坏了细胞膜的选择透过性

C:盐酸破坏了原生质层的选择透过性

D:花青素不溶于水而溶于盐酸

上一题 下一题 0.0难度 选择题 更新时间:2018-01-22 12:47:48

答案(点此获取答案解析)

C

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    Why can't some people even get an inch of what they dream of becoming? Blame it on pure dreaming and lack of surrounding goals for achieving their dreams.

    Setting goals is very significant part of accomplishing and positive actions. It is like scaling(攀爬)a 200 feet construction and marking in the early hours on what feet you would like to reach at this specific period.

    People who set goals literally generate a map of their goal settings in life, marking where they should start, where to study a bit, and where and when to end. Once this map coms into being, it allows the map drawer to check where he is in the scheme(安排)of things and whether or not he is making some planning that will take him closer to his goals.

    By surrounding goals, people will know how they are doing and what they should be doing to get their goals or dreams in life. They will know if they can relax or if they have to double their efforts when they are falling short of what is expected of them.

    Goal surroundings means a person's proactive in dealing with challenges that may affect his plans. Being proactive means one is able to outline possible difficulties that may occur as well as the solutions to these difficulties. By doing this, a person is not easily scared or defeated when challenges occur because he has already prepared for them. He knows they can happen and he has prepared a solution or strategy when that time comes.

    Setting goals will enable people to track their progress in whatever hard work they set out to do. It will help people become more confident in themselves and more motivated to get their plans.