67. by oneself 亲自

66. by bus 乘公共汽车

65. by air mail 寄航空邮件

64. break out　 爆发　 break into "闯入, 破门而入"

63. belong to 属于

62. because of=thanks to 由于

61. be worried/serious about 为……而担心

60. be/get used to+v－ing 习惯于

59. be thankful to sb. 对某人很感激

58. be surprised at 对…...感到惊奇