Life is difficult. But life is no longer difficult when we truly understand and accept it. Most people do not fully see this truth. Instead, they complain about their problems and difficulties. They think life should be easy. What makes life difficult is the process of facing and solving problems. Problems make us sad or lonely or angry. These are uncomfortable feeling. 1) Since life has lots of problems, it is always difficult and full of pain and joy as well. However, when we successfully solve them, we can feel that life is very interesting and pleasant.2) __________ are serious tests that can tell _______ from failure. In school we set problems for the students and encourage them to learn well. 3) We learn through the pain of meeting and working out problems. For this reason, wise people learn to face bravely but to deal with the difficulties in their life.____ 将（1）句译成英文____ 在（2）句的空白处填入适当的词使句意完整、上下文通顺____ 将（3）句译成中文____ We get knowledge in the process of solving the problems.____ 从文中找出最能表达该短文主题的句子
函数y=x2-1x的导数是 （ ）
俄国农奴制和沙皇专制制度阻碍资本主义发展的表现不包括
，原线圈接正弦交流电，副线圈接电动机，电动机线圈电阻为R。当输入端接通电源后，电流表读数为1，电动机带动一质量为m的重物以速度v匀速上升。若电动机因摩擦造成的能量损失不计，则图中电压表的读数为 （ ）