【单选题】Mr. LuXun died in 1936. He _______ a lot of famous novels. A. wrote B. was writing C. has written D. would write
【单选题】炼铁选用的铁矿石不仅要求含铁量高,而且要“有害元素”少.今有铁矿石:黄铁矿(FeS 2 )、菱铁矿(FeCO 3 )、赤铁矿(Fe 2 O 3 )、褐铁矿(2Fe 2 O 3 ?3H 2 O)、磁铁矿(Fe 3 O 4 ),你认为不适宜炼铁的矿石应是( )
【多选题】已知逻辑函数 的真值下表所示, 的逻辑函数式为。( )
A.
A’B’C’D+A’B’CD’+A’BC’D’+A’BCD+AB’C’D’+AB’CD+ABC’D+ABCD’
B.
A’B’C’D’+A’B’CD’+A’BC’D’+A’BCD+AB’C’D’+AB’CD+ABC’D+ABCD’
C.
A’B’D’+A’B’C+B’CD+A’CD+AB’C’D’ +ABC’D+ABCD’
D.
A’B’D+A’B’C+B’CD+A’CD+AB’C’D’ +ABC’D+ABCD’
【单选题】This is ______ Luxun Park, and Mr. Green is ______ head of ______ park.
【多选题】已知逻辑函数 的真值下表所示, 的逻辑函数式为。( )
B.
+(BC’)’)’ B. (AB’+A’B+B’+
【单选题】— I haven't met Mr. Brown for ages. — Oh, he _____ for two years. [ ]