糖酵解时丙酮酸不会堆积，因为（）。

A.乳酸脱氢酶活性很强

B.丙酮酸可在丙酮酸脱氢酶作用下生成乙酰CoA

C.NADH／NAD⁺太低

D.乳酸脱氢酶对丙酮酸的Km值很高

E.可为3-磷酸甘油醛脱氢反应中生成的NADP的受氢体

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.

18（）

A.risk

B.guarantee

C.fault

D.benefit