听力原文:W: With the convenience of bankcards, more and more people prefer bankcards to pe
M: I agree. People like bankcards because they offer greater safety and convenience than personal checks.
Q: What can be inferred from the conversation?
(20)
A.A merchant doesn't know the balance before completing a sale.
B.No security system has yet been devised for personal checks.
C.A personal check is secure at the check stand.
D.The clerk can examine all the bankcards.