Since the outbreak of the global financial crisis in 008, developed economies such as the United States, Japan, and Europe have fallen into the predicament of weak economic growth, and the economic growth rate has always been significantly lower than the pre-crisis level. According to the theory of long-term stagnation, this is due to the continued decline in the equilibrium real interest rate And it has fallen into the negative range, and the central bank is bound by the zero lower limit and it is difficult to reduce the actual real interest rate to the equilibrium real interest rate, so the relatively high real interest rate has led to continued suppression of aggregate demand (especially investment demand). Even if the United States, Japan, and Europe pursue zero-interest-rate policies, the output gap is always negative, and the economy is difficult to recover. According to this theory, some people believe that the Chinese economy is also facing a situation of insufficient investment demand, and the Chinese economy will also fall into a long-term stagnation. If the following items are true, all of them can refute the above conclusions? ['Insufficient investment demand in China is mainly reflected by a sharp decline in private investment demand.', "China's real interest rate has a wider adjustable range, so it is easier to fall to the equilibrium real interest rate.", "Even if the stagnation theory is true, China's current equilibrium real interest rate is still greater than zero.", "The sharp decline in China's investment growth is very different from the nature of insufficient investment demand highlighted by the theory."]