Researchers have struggled to pinpoint specific causes for hiccups, which happen when a person’s diaphragm contracts . However, neuroscientist Kimberley Whitehead has found that these uncontrollable contractions may play an important role in helping infants regulate their breathing.
- involuntarily
- beneficially
- strenuously
- smoothly
Show answer and solution
Solution walkthrough
- Choice A is the best answer because it most logically completes the text’s discussion of diaphragm contractions and hiccups.
- In this context, “involuntarily” means done without any control, or by reflex.
- The text explains that when a person’s diaphragm repeatedly contracts and results in hiccups (which may be beneficial for infants), those muscle contractions are “uncontrollable.” This context indicates that the diaphragm contractions occur without the person’s control.