The duct of Bellini opens into the ........ .

The correct arrangement of layers of detrusor muscles in the wall of the urinary bladder is . . . . . . .

Columns of Bertini in the kidney of mammals are formed as the extension of

The kidney of an adult rabbit is .............

In humans,the primary excretory system consists of:
$I.$ Pair of kidneys
$II.$ One pair of ureters
$III.$ Urinary bladder
$IV.$ Urethra
$V.$ Skin
$VI.$ Lungs
$VII.$ Liver

$A$ man excretes about ........ urine in $24$ hours.