At the time of definition, it has been said that pa is a pointer variable, and the address value of integer variable A is given. In the scanf statement, pa stands for equality and&; An address value of. The computer relies on the value of this address to find the location to store.

B. Obviously wrong, scanf("%d ",a); In this position, a is the value of the address, and a is just a variable name.

C.& ampPa doesn't mean anything at all. In the definition, *pa means that the variable pa is a pointer variable, while in the statement, as long as pa is written, it means a pointer, and *pa means the content stored at that address.

D. has the same effect as B.