After being produced in the seminiferous tubules, sperm mature in the

The answer is epididymus.

Testicles contain seminiferous tubules, in which sperm is produced, and an epididymis, in which sperm matures. Mature sperm passes through the epididymis to the vas deferens. There, it combines with a liquid secretion from the seminal vesicles and continues through the prostate gland to the urethra. Sperm containing fluid is called semen and it is ejected through the urethra.

Abay where the river empties into the sea

Some of her  assignments would be creation of drugs. she is a medical chemist after all so she'd need to have the necessary knowledge to make medicine which can later be sold in a pharmacy