单项选择题
If you husband something valuable, you use it （）。
A.Carelessly B.Optionally C.Carefully D.Freely
判断题 Many startups in Silicon Valley are branching out into new places that the trend has a name, Off Silicon Valleying.
单项选择题 What qualities made the Silicon Valley impossible to clone?（）
单项选择题 （）has the 19th-largest economy in the world.
