Which factors below would keep the skier in the air longer and contribute to a longer jump?
1. The ramp at the end of the in-run is level instead of slightlytilted down.
2. The skier extends his body forward and positions his skisin a V shape.
3. The skier has wider and longer than usual skis,
4. The skier pushes upward off the end of the ramp at the end of the in-run. of the in-run.
5. The skier crouches in a streamline position when going down the in-run.
$$
\begin{array}{ll}{\text { (a) } 1} & {\text { (b) } 5} \\ {\text { (d) } 2,3,4} & {\text { (e) } 1,2,4,5}\end{array}
\begin{array}{l}{\text { (c) } 1,3,5} \\ {\text { (f) } 1,2,3,4,5}\end{array}
$$