Fill in the gaps :
(a) Ascending limb of Henle’s loop is _______ to water whereas the descending limb is_______ to it.
(b) Reabsorption of water from distal parts of the tubules is facilitated by hormone _______.
(c) Dialysis fluid contains all the constituents as in plasma except _______.
(d) A healthy adult human excretes (on an average) _______ gm of urea/day.