致病微生物是常用的生物战剂，在以下描述中，可以将病毒与其他微生物相区别的是[ ]

（12分）重铬酸钠（Na₂Cr₂O₇）广泛用于合成颜料、媒染剂等，以铬铁矿（主要成分为Cr₂O₃，还有FeO、Al₂O₃、SiO₂等杂质）为原料制取重铬酸钠的流程图如下：

请回答下列问题。

⑴铬铁矿中的Cr₂O₃与纯碱、O₂在高温下反应的化学方程式为       ▲      。

⑵若Ⅰ中只用一种试剂调节溶液的pH，应选用    ▲ （填标号）。

A．稀硫酸            B．氧化钠固体            C．氢氧化钾溶液

⑶Ⅰ中，调节溶液pH后，如果溶液的pH过小，可能导致W沉淀部分溶解，原因是：

   ▲   。（用离子方程式表示）。

⑷Ⅱ中，Na₂CrO₄转化为Na₂Cr₂O₇的离子反应如下：

2CrO₄^2－（黄色）＋2H^＋Cr₂O₇^2－(橙红色)＋H₂O

①该反应  ▲ （填“是”或“不是”）氧化还原反应。

②若往Na₂Cr₂O₇溶液（橙红色）中加入足量NaOH固体，溶液  ▲ （填标号）。

A．变黄色            B．颜色不变        C．橙红色变深

③已知：25℃，Ag₂CrO₄的K_sp＝1.12×10^－12，Ag₂Cr₂O₇的K_sp＝2×10^－7。25℃，往Na₂Cr₂O₇溶液中加入AgNO₃溶液，最终只生成一种砖红色沉淀，该沉淀的化学式是  ▲  。

教师的政治地位决定了教师的职业声望、职业吸引力和教师从事该职业的积极性和责任感。

关于玻璃体的特点叙述错误的是（）

A.在视神经周围玻璃体与视网膜结合较紧密

B.玻璃体无血管和神经

C.玻璃体无再生能力

D.玻璃体新陈代谢快，因此可保证其透明性

E.玻璃体对视网膜起良好的支撑作用

依照《中华人民共和国价格法》，经营者销售商品，可以不注明商品的

A．品名

B．产地

C．规格

D．等级

E．用途

When anyone opens a current account at a bank, he is lending the bank money. He may (1) the repayment of the money at any time, either (2) cash or by drawing a check in favor of another person. (3) , the banker customer relationship is that of debtor and creditor who is (4) depending on whether the customer’s account is (5) credit or is overdrawn. But, in (6) to that basically simple concept," the bank and its customer (7) a large number of obligations to one another. Many of these obligations can give (8) to problems and complications but a bank customer, unlike, say, a buyer of goods, cannot complain that the law is (9) against him.

The bank must (10) its customer’s instructions, and not those of anyone else. (11) , for example, a customer opens an account, he instructs the bank to debit his account only in (12) of checks drawn by himself. He gives the bank (13) of his signature, and there is a very firm rule that the bank has no right or (14) to pay out a customer’s money (15) a check on which its customer’s signature has been (16) . It makes no difference that the forgery may have been a very (17) one, the bank must recognize its customer’s signature. For this reason there is no (18) to the customer in the practice, (19) by banks, of printing the customer’s name on his checks. If this (20) forgery, it is the bank that will lose, not the customer.

12（）

A.respect

B.charge

C.line

D.place