Smiles and grimace (A) can be very effective (B) used in conversation, but more commonly (C), we do not tend (D) to think that nonverbal physical response may be communicating.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 46 to 50.

Left-handers are the odd ones out. Sure, lefties (46)            up about 10 percent of the population - but, frankly, it seems like society has forgotten about them. Just consider all of the right-handed gadgets, awkwardly designed desks, and cooking tools that fit comfortably only in your right hand. What (47)             someone to become a lefthander? Scientists aren’t exactly sure, but research points to a complex (48)             between genes and environment. While no exact set of “leftie genes” have been discovered, people who dominantly use their left hands do have more left-handed family members. And researchers have found different brain wirings in righties vs. lefties. But no matter (49)            it is that drives someone to use their antipodal paw, science has also uncovered a particular set of personality traits that left-handed people tend to have. So for all of you lefties, leftie-loving righties, and ambidextrous folks out there - it’s time to brush up on your left-handed knowledge and help (50)            an end to leftie discrimination once and for all.