制作酸奶、甜酒等食品都利用了微生物的发酵技术，发酵时的温度一般要控制在 [ ]

A．10℃左右    

B．20℃左右  

C．30℃左右    

D．40℃左右

Why must we pay taxes The answer is that the government needs money for many things, for example, to pay its soldiers, sailors and airmen, to build roads, bridges, offices, schools, etc, and to buy goods from abroad ; and only the people of the country can supply the money. One of the most important taxes is income-tax which a person pays according to the amount of his income, whether he is a merchant, a doctor, a lawyer, a shopkeeper, a miner or anything else. This is called a "direct" tax, because it is paid in money directly to the government. Another tax is paid on goods such as watches, jewelry, new clothes, tobacco, wine, etc, when they are brought into a country. Such a tax is paid as part of the price of these goods if they are late sold in shops. We call it "indirect" tax, because it is paid indirectly through the shopkeepers. People usually complain about having to pay taxes, but they forget that the money is spent on things that they and their families need. We need policemen to catch thieves, to see that men obey the laws, to direct traffic, etc, and they must be paid what they earn; children need education, and there must be schools and teachers; we want our streets to be kept clean, and the wages of men who do this kind of work have to be paid. Above all, the country must always be ready to defend itself against attacking enemies, and we can’t have an army without paying for it. Besides, if a country wants to develop, there are many other things to do... Taxes, therefore, cannot be avoided. We buy our food and clothes and pay for our amusements; but, there are several things that the State finds the money for, and that is necessary for us if our society is to continue. We have no real reason to complain, therefore, when we are asked to supply money to be spent for the good of ourselves and for our fellow-citizens.