https://www.reuters.com/article/us-china-tech/teslas-musk-alibabas-ma-talk-aliens-and-ai-skip-issues-like-trade-idUSKCN1VJ0RG >Tesla CEO Elon Musk and Alibaba founder Jack Ma discussed Mars and artificial intelligence but steered clear of the U.S.-China trade war in their first joint appearance on Thursday that some audience members said was disappointing.