Which of the following sentences contains an error?
a. do you know anyone who is studying science?
b. i had no choice but to except the invitation.
c. dentists recommend flossing teeth daily in order to avoid plaque buildup.

5. the following question refers to the four selections by albert einstein: these readings show that, between 1939 and 1952, einstein a) abandoned science and turned to political activism. b) revised his opinions about the need for nuclear weapons. c) worked tirelessly to abolish nuclear weapons. d) devoted himself solely to scientific research.