谐振式开关是由下列器件组成的()。
A. 开关
B. 电感
C. 电容
D. 电阻
Choose the most correct statements about SMTP/ESMTP. ()
A. Open mail relays are often used for spamming.
B. ESMTP does NOT provide more security features than SMTP
C. SMTPdoes provide authenticated email sending."
D. Worms often spread via SMT
母联、分段开关回路作业时,应退出作业开关的()压板。
我国《担保法》规定地担保物权包括()。(担保法第42条)
A. 典权和抵押权
B. 留置权、抵押权和质权
C. 地上权和地役权
D. 地役权、典权和质权