Assuming he's still alive, how old would he be now?
假定他还活着，现在有多大年纪了？
I was glad to hear you're alive and well.
听说你健在我很高兴。
She's alive ─ her heart is still beating.
她没死——她的心脏还在跳动。
There is little hope that they will be found alive.
活着找到他们的希望很渺茫。
We don't know whether he's alive or dead.
我们不知道他是死是活。