下列 CHECK 约束条件中哪个总是有效的？&#91; &#93; A: CONSTRAINT gender_chk CHECK(gender IN (N'男',N'女')) B: CONSTRAINT birthday_chk CHECK(birthday > GETDATE()) C: CONSTRAINT mark_chk CHECK(mark<560) D: CONSTRAINT address_chk CHECK(address LIKE N'广州市%')

A．E-mail address and IP address B．MAC address and port address C．MAC address and IP address D．port number and IP address

【单选题】In the description of IPv4 address and IPv6 address, the correct one is (). A. IPv4 address and IPv6 address are 32 bits B. IPv4 address is 32 bits, IPv6 address is 128 bits C. IPv4 address and IPv6 address are 128 bits D. IPv4 address is 128 bits and IPv6 address is 32 bits

The __________ address is the address of the writer.

The address in letterhead is the address of the ___。

The inside address is the address of the writer.

1M1T架控切除切除的开关为（）。 A: CHK B: CHRE C: FC D: LB

which address signals are used to generate the chip select signal of the memory chip for the one-to-one mapping of the memory chip to the logical storage space of the computer system? A: some of the high-order address signals of the address bus B: the lower-order address signals of the address bus C: all remaining high-order address signals of the address bus D: One of the remaining high-order address signals of the address bus

Which IP address is a network address?

Inside address includes the name and address of the ________.