Read this line from "the Song of Wandering Aengus" by William Butler Yeats. And walk among long dappled grass, What does "long dappled grass" mean? It suggests spots where sunlight is shining on it. The grass is flattened by people walking on it. It shows the texture and movement of the grass. It suggests that the grass is tall and in need of cutting.

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.