The pipa is a pear-shaped, four-string instrument used mainly in music. american
mexican
african
chinese

Idon't know which one from these two forms is correct! "he believed that the technology of the future would allow robots to do the same tasks as a human." or "he believed that the technology of the future would have allowed robots to do the same tasks as a human. , it's ! i need your !

1. in which sentence is the underlined portion a predicate nominative? for astronauts, going into space to repair orbiting equipment becomes a challenge. for astronauts, going into space to repair orbiting equipment becomes tricky. for astronauts, going into space to repair orbiting equipment becomes challenging. for astronauts, going into space to repair orbiting equipment becomes frequent.

How would you check a statement to determine that it is a simile?