The following sentences also appear in the reading comprehension passages. I would be much grateful if you could help me.
1)But Skoll has seen the transformative power of entrepreneurship so often, from eBay to Africa, that you wouldn't want to bet against him. (In this sentence, what does "entrepreneurship" mean and what does "bet against him" mean?)
2)Mental practice can actually increase real world strength and performance,.. Pumping virtual iron physically changes the brain—and the brain, after all, controls the body. (In this sentence, what does " Pumping virtual iron " mean?)
3)Imagine, in your mind's eye, a harp in all its graceful detail; the same region of your visual cortex just turned on as if you actually looked at the instrument. (In this sentence, what does " the same region of your visual cortex " mean, esp. "the same region"?)
4)But just as physicians are showing that something as inchoate as a positive outlook can affect something as real as the progress of breast cancer, so scientists are uncovering how mental imagery and other tricks of the athlete's trade affect the real, physical brain and hence the body. (In this sentence, what does " as inchoate as a positive outlook " mean?)