Part V: Incomplete Sentences Directions: A word or pharse is missing in each of the sentences below. Four answer choices are given below each sentence. Select the best answer to complete the sentence. Then mark the letter (A), (B), (C) or (D) on your answer sheet.
51. Considering the failure of -------- system to offer adequate support, we might have to provide refunds to our customers.
Our aim is to increase the efficiency of the rail services both for freight and passengers by providing services on the network and increasing -------- among companies.
về câu hỏi!