This is a tech forum, so we can go down a list of US tech companies, giving their 2017 revenue from China:
* Apple: $45 billion (20% of Apple's total)
* Intel: $15 billion (its largest market, 24% of total)
* Qualcomm: $15 billion (>60% of Qualcomm's total)
* Micron: $10 billion (>50% of Micron's total)
* Broadcom: $9 billion (>50 of Broadcom's total)
* Cisco: $8 billion (15% of Cisco's total)
The list goes on and on, but you get the picture.
The numbers come from here: https://www.marketwatch.com/story/trade-war-watch-these-are-...