G Which are structures of the excretory system? Select four options.
kidney
spleen
O bladder
esophagus
O ureter
O urethra

The answer are A c e f

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

geologic time scale (for gradpoint) =)