Question

求英语帝

From September 1 on,______cellphone customers have to present ID when buying___ phone number.
A 不填，the B the,the C 不填,a D the a

Answer 1

From September 1 on,（不填）cellphone customers have to present ID when buying (a) phone number.
自九月一日起，手机用户需持身份证购买电话号码。
后一个不用冠词，因为不是特指的哪个号码，前面因为是复数，不是特指，因此不能用the

因此答案是：C

Answer 2

D