China Mobile has to face the problem that more and more people in China prefer to choose ________ cheaper wireless phone service known as ________“Little Smart”．
A.a; theB.a; 不填C.the; 不填D.the; the在线课程B
解析：
“选择一种廉价的无线电话服务”，此处表“种类”，应用不定冠词。Little Smart(小灵通)相当于专有名词，其前不用冠词。