For the past ten years we have been selling various durable goods to wholesalers and large retailers in all the major cities of China, and______a considerable number of well-established connections.
For the past ten years we have been selling various durable goods to wholesalers and large retailers in all the major cities of China, and______a considerable number of well-established connections.
A.has built
B.has built up
C.have built
D.have built up
