Which of the following is NOT true of meditation a. It relieves the pain of cancer. b. It counteracts the effect of depression. c. It has mystic elements. d. It has long been used as a cure-all.

为保证人孔内光缆安全，应将人孔内光缆及接头盒（）。绑扎固定接头盒时，其两端缆线不可绷紧，应有一定（），盘留、收拉预留缆线时，接头盒（）。