Problem: Text: Estrogens are synthesized in all vertebrates as well as some insects. Their presence in both vertebrates and insects suggests that estrogenic sex hormones have an ancient evolutionary history. The three major naturally occurring forms of estrogen in females are estrone (E1), estradiol (E2), and estriol (E3). Another type of estrogen called estetrol (E4) is produced only during pregnancy. Quantitatively, estrogens circulate at lower levels than androgens in both men and women. While estrogen levels are significantly lower in males compared to females, estrogens nevertheless also have important physiological roles in males.

Question: is there such a thing as natural estrogen?
A: yes

Problem: Text: There are no survivors; Linda reads the eulogy at the memorial, followed by her remembering Billy's voice soliloquising about what it means to be a swordboat captain.

Question: does the crew die in the perfect storm?
A: yes

Problem: Text: The liger is a hybrid offspring of a male lion (Panthera leo) and a female tiger (Panthera tigris). The liger has parents in the same genus but of different species. The liger is distinct from the similar hybrid tigon, and is the largest of all known extant felines. They enjoy swimming, which is a characteristic of tigers, and are very sociable like lions. Notably, ligers typically grow larger than either parent species, unlike tigons.

Question: can you cross a lion and a tiger?
A:
yes