in arabian countries ground water is already used three times quicker than it can be replenished, and
in mexico city water supplies could be exhausted in the next ten years.

밑줄친 could be exhausted 는 왜 과거형으로 be p.p를 가진 수동태형이 된거죠..?
in은 after로 쓰인게 아닌가요? 그렇다면 can be exhausted가 아닌지요..??