心情愉快是儿童青少年心理健康的核心．保持心情愉快的方法有以下三种：

方法一：____；方法二：____；方法三：____．

函数f（x）=$\sqrt{2x-1}$+x的值域是（　　）

    Robert and Henry were going home from school, when, on turning a corner, Robert1out, "A fight! Let us go and see!" "No," said Henry; "Let us go quietly home and avoid this quarrel. We have2to do with it, and may get into trouble."

    "You are not a brave boy, and afraid to go, "said Robert, and off he ran. Henry went straight home, and in the afternoon went to school, as usual,3 Robert had told all the boys that Henry was a coward, and they laughed at him a great deal.

    A few days4, Robert was bathing with some schoolmates and 5his depth. He struggled and screamed for help, but all in vain. The boys 6 had called Henry a coward, got away from the water as fast as they could, but they did not even try to help him. Robert was fast 7, when Henry threw off his clothes, and sprang into the water. By great effort, and8much danger to himself, he brought Robert to the shore, and thus saved his life.

    Robert and his schoolmates were9at having called Henry a coward. They admitted that he had more10than any of them.

    Never be afraid to do good, but always fear to do evil.

竖直向上抛出一个小球，抛出后小球继续向上运动，这是因为小球具有____；在向上运动一段距离后，速度逐渐变小，然后下落，这是因为小球受到____作用而改变了它的运动状态；在小球上升到最高点后，若此时受到的力全部消失，小球将处于____（静止/匀速直线运动）．