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如图所示,用14N的水平拉力F拉滑轮,可以使重20N的物体A以0.2m/s的速度在水平地面上做匀速直线运动.若不计滑轮重和绳重,下列说法正确的是(  )

A:地面受到的滑动摩擦力为7N

B:滑轮移动的速度为0.4m/s

C:水平拉力F做功的功率为2.8W

D:在2s内绳子对物体A所做的功为2.8J

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A,D

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    Whether you're a child, teenager, young adult or are middle-aged, respecting your parents is an important value. Your parents are the people who raise you, devoting time, energy and money to your development.____Whatever your age, there are 4 ways to show respect.

    Respect their belongings.

    One important way to show respect is to show regard for the things important to your parents. For younger children, this may mean not touching jewelry or other valuable things.____Don't take advantage of your parents' kindness and generosity. And never borrow things without asking first.

    Punctuality

    ____Therefore, always be on time. For teenagers, showing up on time means coming home by curfew (宵禁). Adult children should show up on time for family dinners or events, or to pick a parent up for a medical appointment. Call if you're going to be late because parents worry about children, whatever their age.

    ____

    Remembering birthdays, anniversaries and other special days is a sign that you honor your parents. Make plans to take them to lunch or dinner or bake a cake or cookies. Most parents don't expect expensive gifts, but a handmade gift is always appreciated, a phone call from a grown child who lives too far for a visit is a welcome sign of respect.

    Be kind.

    Kind words and affection are simple ways to show respect. Tell your parents you love them. Listen and allow your parents to speak without interruption. Show a sincere interest in what your parents have to say. Be patient with your parents and don t rush them. Never talk back or be rude or disrespectful. Acknowledge your parents' achievements. ____

A. Parents should help children build self-confidence.

B. Celebrate with them.

C Lateness shows a lack of respect.

D. Treat your parents the way you would like to be treated.

E. And they love you unconditionally throughout your life.

F. Being respectful helps build positive relationships with others.

G. For grown children, respect may mean returning a borrowed tool in good condition and on time.