Most people have jobs. They go to1 nearly every day. Some people are lucky. Either they have very interesting jobs or they can make a lot of money. Most people are not so lucky. Either their jobs are not very interesting or they don't make a lot of money.

    The most interesting jobs are often the most2. It3a long time to learn how to do them. Doctors study for at least 6 years after finishing school. Airline pilots study for longer. They have to learn to4in small planes first, and then5move up to bigger and bigger planes. Most airline pilots are at least 30 years old.

    Some young people have interesting and well-paid jobs. Many successful6are young. Football and tennis stars are usually under 35 years old. Older people usually can't play these sports very well. They cannot move fast enough. Golf, however, is a good sport for7people.

    Most people work until they are 60 or 65 years old. Then they retire (退休) and have a lot of8time. Some people9retire. These people usually have very interesting jobs10 artists, musicians, and actors usually work until they die. Their work is their life.

材料一    吾国今日道德之根本问题，乃在革除昔日一本不易旧道德之观念，而建设今日因时制宜新道德之标准。就目前之情势观之，应规定者约有三事：（一）注重人道主义．以平等博爱诸德实行之；（二）发达个人之制己心；（三）主张极端之自由思想。

——吴康《论吾国今日道德之根本问题》

材料二   自西洋文明输入吾国，最初促吾人之觉悟者为学术，相形见绌，举国所知矣；其次为政治．年来政象所证明已有不克守缺抱残之势。继令以往，国人所怀疑莫决者, 当为伦理问题。此而不能觉悟，则前之所谓觉悟者，非彻底之觉悟，盖犹在惝恍迷离之境。吾敢断言曰：伦理的觉悟，为吾人最后之觉悟。

——陈独秀《吾人最后之觉悟》

材料三   我们今日的环境，真是不幸极了：社会的种种组织，风俗，制度，都是过渡时代、“青黄不接”——新文化未能完全产出，旧道德已宣告破产；使得国内的军政，民政，以及工商百业，都显出一种黯淡凋零的状态，比之欧洲黑暗时代，也差不多。

——左立夫《中学毕业生的切身问题）

回答问题

①转动粗准焦螺旋    ②调节光圈     ③转动细准焦螺旋

④转动转换器        ⑤移动玻片标本．

如图所示，将力F分解为F₁和F₂两个分力，已知F₁的大小和F₂与F之间的夹角α，且α为锐角，则（   ）