North American Class 8 truck orders in February remained below year-ago comparisons for a second consecutive month after a short uptick in December, according to ACT Research.

Vitousek, P. M. et al. Human alteration of the global nitrogen cycle: sources and consequences. Ecological Applications 7, 737–750 (1997).

This article brings you the CBSE Class 9 Science notes on chapter 14 ‘Natural Resources’ (Part-II). In the previous part, of this chapter, you learned about Natural Resources and their types.