Explanation:
Hole. Hole. Different notes can be played on the flute by blocking holes. ...
Drum skin. Drum skin. Hitting the bongo drum makes its tight elastic skin vibrate.
String. String. ...
Sound. hole. ...
Bow. Bow.
The question is looking for "ellipse" and "two" to fill in the blanks.
There are different types of contact forces like normal Force, spring force, applied force and tension force.