That is why some of the most successful companies in the world, such as 3M and Google, encourage their employees to 18 all sorts of relaxing activities, such as playing pinball and wandering about the campus.
答案：(C) take part in
【句型】take part in 固定片語「參與」；refer to（提及）、answer for（對……負責）、put up with（忍受）都不合。
四個選項都是「動詞＋介系詞」的片語，長得很像，很容易靠語感亂猜。其實只要抓住受詞是什麼，這一格就穩了。
空格後面是 all sorts of relaxing activities（各式各樣的放鬆活動），前面是 encourage their employees to（鼓勵員工去……）。「參加活動」用的就是 take part in，你國中背過 take part in a contest（參加比賽），直接搬過來用。同樣意思的說法可以一起記：participate in（參與，語氣比較正式）、join in（加入一起做）。這裡要特別分清楚 join 和 join in：join a club 是加入社團成為成員，join in the game 是加入一起玩這場遊戲，前者接團體，後者接活動。
refer to（提到；指的是）後面接被提及的對象，不是活動。answer for（為……負責）是承擔責任。put up with（忍受）語意最容易被排除——前面的動詞是 encourage（鼓勵），公司鼓勵員工去「忍受」打彈珠台和在園區裡閒晃，明顯不合理。
take part in（參加）、participate in（參與）、join in（加入一起做）、join + 團體（加入某個團體）、all sorts of（各式各樣的）、refer to（提到；指的是）、answer for（為……負責）、put up with（忍受）、wander about（四處閒晃）。
It has long been assumed that creativity is some unusual trait enjoyed by the few. However, according to a wide array of scientific and sociological research, creativity is 16 a sign of rare genius than a natural human potential. Thus, it can be nurtured and encouraged.
It is believed that taking breaks from a problem can help 17 a moment of insight or stimulate new ideas. Unconventional solutions can also be explored. That is why some of the most successful companies in the world, such as 3M and Google, encourage their employees to 18 all sorts of relaxing activities, such as playing pinball and wandering about the campus. During such breaks, the mind turns inward, 19 it can subconsciously puzzle over subtle meanings and connections.
Another way to increase creativity is to take risks. This is because many breakthroughs come up when people venture 20 their usual routines or areas of expertise. This can be done by, for example, learning new skills or traveling to new countries.