圆锥的体积比圆柱的体积小.______.
因为圆柱和圆锥是在“等底等高”的条件下,圆锥的体积是圆柱体积的13,而题干没有说到圆柱、圆锥的高和底,
所以无法比较大小,
故答案为:×.
下列关于建设工程施工合同履行过程中发包人的支付责任表述错误的是( )。
A.发包人应在双方计量确认后14 d内向承包人支付工程预付款B.发包人超过约定的支付时间不支付工程进度款,承包人可向发包人发出要求付款的通知C.发包人在收到承包人通知后仍不能按要求支付的,可与承包人协商签订延期付款协议,经承包人同意后可以延期支付D.延期付款协议中须明确延期支付时间,以及从计量结果确认后第15天起计算应付款的贷款利息
Potato cyst nematodes are a pest of potato crops. The nematodes can lie dormant for several years in their cysts, which are protective capsules, and do not emerge except in the presence of chemicals emitted by potato roots. A company that has identified the relevant chemicals is planning to market them to potato farmers to spread on their fields when no potatoes are planted; any nematodes that emerge will soon starve to death. Which of the following, if true, best supports the claim that the company’s plan will be successful
A.Nematodes that have emerged from their cysts can be killed by ordinary pesticides.
B.The only part of a potato plant that a nematode eats is the roots.
C.Some bacteria commonly present in the roots of potatoes digest the chemicals that cause the nematodes to emerge from their cysts.
D.Trials have shown that spreading even minute quantities of the chemicals on potato fields caused nine-tenths of the nematodes present to emerge from their cysts.
E.(E) The chemicals that cause the nematodes to emerge from their cysts are not emitted all the time the potato plant is growing.