When investing, it's always good to be plunking your hard-earned dollars into companies and industries that you understand. A biotech company may sound exciting, but if you aren't very familiar with that industry, you may not appreciate the risks it faces. One of the most understandable industries is the retail sector, and one of the most solid retailers is Costco (NASDAQ: COST). Image source: Getty Images. Where to invest $1,000 right now? Our analyst team just revealed what they believe are the 10 best ...