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★ It was not immediately obvious that water was     1     the development of life.

★ This produced   2  , which made it possible for life to develop.

★ I earned my passage by working as an unpaid hand, which   3  .

★ When they crossed the Rocky mountain, they    4   some mountain goats and even

      a grizzly and an eagle.

★ Many of them   5  riding wild horses and can win thousands of dollars.