SHANGHAI—American companies occupy choice real estate at a mega-Chinese trade show here but also stand at an uncomfortable intersection: between the huge business opportunity of the China market and a U.S. president critical of their investment in it.
Artificial grass from DowDuPont Inc., Dell Technologies Inc. laptops, a limousine with windows darkened by 3M Co., candy bars from Mars Inc. and almonds from Costco Wholesale Corp. are calling to buyers at the world’s largest trade-show venue this week. The strong American turnout...