简述羊足碾、汽胎碾、振动碾各适合压实哪几种土料？
发行人自股份有限公司成立后，持续经营时间应当在（）年以上，但经国务院批准的除外。 ["1","2","3","5"]
投影
相同的投入，下列哪种期权投资策略可能有最大收益（） ["买入看涨期权","卖出看涨期权","买入看跌期权","买出看跌期权"]
A co-worker uses a gadget from the Windows Sidebar feature on their computer. You examine your computer and find that the gadget is not on the list of available gadgets. You need to add this gadget to the Windows Sidebar feature on your computer. What should you do?（） ["A","B","C","D"]
我国的水资源问题是什么？突出表现在哪几个方面？
