What resource accounts for roughly 90% of botswana's export earnings?

The resource that accounts to be Botswana's 90% export earnings is "Diamonds." Diamond has many unequaled qualities and is very unique among minerals. It is the hardest known substance, it is the greatest conductor of heat.

I hope this helps and that you have a good day! :)

when the chinese communist party took power in 1949, it began to build new di and levees to hold the yellow and yangtze rivers back.