becoming是什么意思

　　The humidity was becoming unbearable.

　　这种潮湿使人越来越难以忍受了。

　　His memory was becoming shockingly bad.

　　他的记忆力正变得很糟。

　　Mother was becoming too frail to live alone.

　　母亲已逐渐衰弱到无法独居。