问题
选择题
There is an ongoing debate about the potentially harmful effects ________ text messaging can have on people's grammar.
A．what
B．who
C．that
D．whose
答案
答案：C
句意：有关发短信对人们语法的潜在危害的辩论正在进行。先行词为the potentially harmful effects，在定语从句中作宾语，定语从句可还原为“text messaging can have potentially harmful effects on people's grammar”，且先行词指物，故选that。