並前往https://books.google.com.tw/books?id=mCsTEAAAQBAJ&pg=PA53&lpg=PA53&dq=focus%E4%BA%94%E9%96%80&source=bl&ots=uSMHbvJGMs&sig=ACfU3U2TvywH-PlFPTYMv3rl5Nlyel67gg&hl=zh-TW&sa=X&ved=2ahUKEwiatM6C6PaBAxVdgP0HHa2-Al0Q6AF6BQjFARAD