[经] direct write-off method for uncollectibles

dāi zhàng zhí jiē xiāo zhàng fǎ ㄉㄞ ㄓㄤˋ ㄓˊ ㄐㄧㄝ ㄒㄧㄠ ㄓㄤˋ ㄈㄚˇ