The first one is asking about the amount of plant species in the rain forests. So the answer would be about 1/5.
The second one about the coal and oil is asking about when the next time the coal and oil are able to be used as fuel again. So the answer would be in the millions.
The third question is asking how much time until the oil is gone. So based on some research I would say 100 year for that one.
The fourth one is asking about which natural resource is only limited to a certain amount. This one would be trees.
The last one is asking about how actions are affecting natural resources. This one is Human.