已知△ABC的外接圆的圆心为O，半径为1，若$3\overrightarrow{OA}+4\overrightarrow{OB}+5\overrightarrow{OC}=\overrightarrow{0}$，则△AOC的面积为(      )

如图，△ABC中，BC=2，DE是它的中位线，下面三个结论：（1）DE=1；（2）△ADE∽△ABC；（3）△ADE的面积与△ABC的面积之比为1：4．其中正确的有（　　）

    Youth sport has the potential to accomplish three important objectives in children's development. First, sport programs can provide youth with opportunities to be physically active, which can lead to improved physical health. Second, youth sport programs have long been considered important to youth's psychosocial development, providing opportunities to learn important life skills such as cooperation, discipline, leadership, and self-control. Third, youth sport programs are critical for the learning of motor skills; these motor skills serve as a foundation for future national sport stars and recreational adult sport participants. When coachers develop activities for youth practices and when sport organizations design youth-sport programs, they must consider the implication of deliberate play and deliberate practice.

Research from Telama （2006） states that regular participation in deliberate play or deliberate practice activities during childhood and youth （ages nine to eighteen） increases the likelihood of participation in sports during adulthood by six times for both males and females. Côté （2002） defines deliberate play activities in sport as those designed to maximize enjoyment. These activities are regulated by flexible rules adapted from standardized sport rules and are set up by the children or by an involved adult. Children typically change rules to find a point where their game is similar to the actual sport but still allows for play at their level. For example, children may change soccer and basketball rules to suit their needs and environment （e.g. in the street. on a playing field or in someone's backyard）. When involved in deliberate play activities, children are less concerned with the outcome of their outcome of their behavior. （whether they win or lose） than with the behavior. （having fun）.

    On the other hand, Ericsson （1993） suggests that the most effective learning occurs through involvement in highly structured activities defined as deliberate practice. Deliberate practice activities require effort, produce no immediate rewards, and are motivated by the goal of improving performance rather than the goal of enjoyment. When individuals are involved in deliberate play, they experiment with different combinations of behaviors, but not necessarily in the most effective way to improve performance. In contrast, when individuals are involved in deliberate practice, they exhibit behavior. focused on improving performance by the most effective means available. For example, the backhand skills in tennis could be learned and improved over time by playing matches or by creating fun practice situations. However, players could more effectively improve their backhand performance by practicing drills that might be considered less enjoyable. Although drills are used in most effective means available practice might not be the most enjoyable, they might be the most relevant to improving performance.

    （Note: Answer the questions or complete the statements in NO MORE THAN TEN WORDS）

读我国南部沿海省区城市分布略图，完成下题。

与甲省相邻乙、丙两省区的简称分别是（   ）

    One day, a poor young man went to Paris to visit one of his father's friends and 1 that his father's friend could help him find a simple job for living.

    "Are you good at math," his father's friend asked him.

    The young man shook his head.

    "How are your history and geography?"

    The young man shook his head again.

    "How about your law?"

    The young man 2 his head embarrassedly.

    His father's friend asked again and again,3 the young man could only shake his head and told him he himself couldn't find out any4.

    "Then write down your address first."

    The young man wrote down his address and turned to leave, but he was stopped by his father's friend. "Your name is written very 5 which is your advantage. You shouldn't satisfy yourself with finding a job only for 6"

    Years later, the young man wrote the classical works that won the world fame. He was Alexandre Dumas, a famous French writer of 18th century. One of his greatest works 7 The Three Musketeers was popular 8 a great number of readers.

    There are many ordinary persons in the world who all have many 9advantages, but they are neglected (忽视) because of their self-abasement (自卑). In fact, there is a gold mine (矿) in every ordinary life. If you're willing to dig, you will dig out treasures to 10 yourself.