Qixin Lime Company, located in Tangshan, Hebei Province, is the largest private cement industry in old China. The highest output reached 270,000 tons before 1934, and then the output decreased obviously. 1947 was restored to160,000 tons, and 1948 was reduced to130,000 tons, which was enlisted for military use. After 1934, the objective reason for the deterioration of the company's operation is ()
① Lack of funds, weak technology and poor product competitiveness ② Bureaucratic capital suppression and civil war policy of the National Government ③ Japan's economic plunder ④ American economic aggression.
A.①②③④ B.①③④ C.①②③ D.②③④
Analysis: This question examines students' analytical ability. According to the "external cause" in the stem, we can know that it is 234. Answer: d