Соедините или измените следующие предложения по образчику, используя конструкцию трудное

Объедините либо измените следующие предложения по образчику, используя конструкцию трудное добавленье.
Эталон: It is known to every economist that an increase in the price of a factor will reduce demand for it. gt; Every economist knows an increase in the price of a factor to reduce demand for it.
The rate of unemployment in tourist areas is higher than in highly industrialized ones. Economists know this.
It is well known to economists that the motives for nationalization are political as well as economic.
As prices for fuel and electricity have risen, we expect an increase in all prices.
The degree of profitability in private enterprises is higher than in the public sector. Some economists think so.
Many experts think that the growing use of fertilizers and other chemicals presents a danger to the environmen