A new case study says Chinese companies face tough in the US and have a long way to go to

问题补充：

A new case study says Chinese companies face tough in the US and have a long way to go to be successful.

A. challenges

B. campaigns

C. motivations

D. dilemmas

答案：

(答案→)A. challenges

B. campaigns

C. motivations

D. dilemmas

解析：考查名词辨析。句意：一项新的案例研究显示，中国的公司在美国面临着严峻的挑战，在通往成功的路上还有很长一段路要走。A挑战，难题；B运动，活动；C动机；D窘境，困境。故选A。