62. To be a good leader, you should _______. (A). not be afraid of any risks (B). think twice before taking risks (C). try to avoid any possible failures (D). know what a thoughtless exercise is

64.　　　　　　　　　　　　　　　　　　　　　　 The writer uses the two questions at the beginning of the passage to _______. (A). test the readers' knowledge about waves (B). draw the readers' attention to the topic (C). show Jamie Taylor's importance (D). invite the readers to answer them