... be careless about 不关心，不在乎 be careless with疏忽，不注意 be careless of 不关心，不把......放在心上 ...
双语例句
1
Other systems can more easily afford to becarelesswith a couple of megabytes here or there; the MVP really has to work very hard on keeping everything small.
其他系统有能力轻而易举地忽略这里或者那里的数兆字节，但MVP必须竭力保持一切最小。
2
Eventually, I got carelesswith the gas can, not bothering to recap it between killings, and there came then, naturally, a match that refused to be lit.
最后，我变得粗心大意，不再麻烦地每次都盖好汽油罐的盖子了，自然，也会因为一根火柴擦不亮而不耐烦。
3
Of everything in life we tend to be most carelesswith our words, yet they are powerful and worthy of care.