1. lose track of 失去音讯
Rose and I remained in touch for a few years via periodic phone calls, but after awhile we lost track of one another.
接下来的几年里，我们通过定期打电话来保持联络，但不久我们便失去了彼此的音讯FG0N8SCCZ^r%([J_@。

2. check up on 核对；察看某人的情况
I was on my way to bed and had wanted to check up on the kids first.
我正准备上床睡觉，然后就想先去察看一下孩子的情况ZSgNYNf*Vla8_PN2。

3. be unaccounted for 下落不明
A passenger train with an unknown number of people aboard was unaccounted for on a line outside Sendai, Kyodo News reported.
一列客车，载员人数未知，已在仙台附近失去联系，下落不明VTWdzHEjvu#o。

4. either way无论是两种情况中的哪一种
To be reborn as a dog or to slander the teacher, either way, is quite a pity!
无论是转世为狗，还是辱骂上师，都是十分可怜的y5&ORKi&y+8。