What fraction/percentage of the U. S.'s bees has died since 1988?

In which way are mercury and venus similar? they both rotate from east to west. they are both small and rocky. they both have thick atmospheres. they both are similar to earth in structure.

Rarefaction is used for which of the following? a. creating a representative sample b. studying how disease impacts populations c. rediscovering species thought to be instinct d. determining which sea creatures live in an area

The relationship between intron and exon