1 There is no knowing where she has gone
== It is impossible to know where she has gone.
2 There is no telling what our Earth will be like in 25 years' time
=== It is impossible to tell what our Earth will be like in 25 years' time
1 There is no knowing where she has gone
== It is impossible to know where she has gone.
2 There is no telling what our Earth will be like in 25 years' time
=== It is impossible to tell what our Earth will be like in 25 years' time