【单选题】The boy stood his head down, listening to his mother scolding him for breaking the windows.
【判断题】电流型并联谐振逆变电路负载两端电压波形弦波。
【简答题】The boy pressed his nose a______ the window, looking outwards at the children playing in the street.
【单选题】Only when his mother arrived ___________.
A.
the boy stopped crying
B.
stopped the boy crying
C.
the boy did stop crying
D.
did the boy stop crying
【判断题】电流型并联谐振逆变电路负载两端电压波形是很好的正弦波 ( )
【单选题】The boy did his homework with the help of his father in the past. But now he can do it alone .
【单选题】How did the President treat the boy who had lost his father?
A.
He asked the boy to leave immediately.
B.
He accepted a typewriter as a gift from the boy' s mother.
C.
He would rather stay alone with the boy.
D.
He would help the boy and the poor family.
【单选题】VPN实现网络安全的主要措施是 (48) ,L2TP与PPTP是VPN的两种代表性协议,其区别之一是 (49) 。 (48)