In cities with rent control, the city government sets the maximum rent that a landlord can charge for an apartment. Supporters of rent control argue that it protects people who are living in apartments. Their rent cannot increase; therefore, they are not in danger of losing their homes. However, the critics say that after a long time, rent control may have negative effects. Landlords know that they cannot increase their profits（赢利）. Therefore, they invest（投资）in other businesses where they can increase their profits. They do not invest in new buildings which would also be rent controlled. As a result, new apartments are not built. Many people who need apartments cannot find any. According to the critics, the end result of rent control is a shortage of apartments in the city.
Some theorists argue that the minimum wage law can cause problems in the same way. The government sets the minimum that an employer must pay workers. The minimum helps people who generally look for unskilled, low paying jobs. However, if the minimum is high, employers may hire fewer workers. They will replace workers with machinery. The price, which is the wage that employers must pay, increases. Therefore, other things being equal, the number of workers that employers want decreases. Thus, critics claim, an increase in the minimum wage may cause unemployment. Some poor people may find themselves without jobs instead of with jobs at the minimum wage.
57．There is the possibility that setting maximum rent may .
A．cause a shortage of apartments
B．worry those who rent apartments as homes
C．increase the profits of landlords
D．encourage landlords to invest in building apartment
58．According to the critics, rent control .
A．will always benefit those who rent apartments
B．is unnecessary
C．will bring negative effects in the long run
D．is very necessary
59．The problem of unemployment will happen .
A．if the minimum wage is set too high
B．if the minimum wage is set too low
C．if the workers are unskilled
D．if the maximum wage is set
60．The passage tells us .
A．the relationship between supply and demand
B．the possible results of government controls
C．the necessity of government control
D．the urgency of getting rid of government controls