一战斗机飞行员驾驶飞机在万米高空的竖直平面内做匀速圆周运动，飞行速度为1080km/h，已知在最低点时飞钒的加速度为60m/s²（取g=10m/s²）

下图是20世纪30年代美国某一重大改革中的宣传画（图中文字为：Work  Pays  America）。它反映了政府

    In China, the history of people planting and using bamboo can date back as far as 7000 years. As early as the Shang Dynasty, bamboo was being used in ancient peopled dally lives. It was used for food, clothing, housing, transportation,____ (music) instruments and even weapons.

    The ____(apply) of bamboo in science and technology is thrilling. In 251 BC, Li Bing, in Sichuan,____ (lead) the local people in building the Dujiang Weirs, the first irrigation network in the world, in which bamboo played ____important role. The world’s oldest water piper was also ____ (make) of bamboo. During the Han Dynasty, the people in Sichuan ____(success) sank a 1600-metre-deep well with thick bamboo ropes. This technology did not spread to Europe____the 19th century, and it was by using the technology ____ the Americans drilled the first oil well in Pennsylvania in 1859.

    In Chinese culture, bamboo is well-known as ____of the “four gentlemen” in plants. To many distinguished men，bamboo is a symbol of goodness and honesty. It is always closely related to people of positive spirits. Bamboo culture contributes to encouraging People to hold on when ____(face) tough situations.