下列操作或做法正确的是（　　）

A．未经老师允许，擅自把实验室的药品带回家

B．用滴管滴加液体完毕，把它放在桌面上

C．在实验室中用尝味道的方法鉴别食盐和蔗糖

D．实验完毕把仪器洗涤干净，并整理好实验桌

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. (254 words)

18（）

A.risk

B.guarantee

C.fault

D.benefit