【简答题】(用cut in , cut into ,cut off, cut down填空)The ship was ______ several pieces in the accident
【单选题】 The ship cut her way _____ the waves.
【简答题】假设一信道带宽为4kHz,信道若要达到24kb/s的传输速率,问: (1)按奈奎斯特公式,需要多少个电平表示数据? (2)按香农公式,信道的信噪比是多少倍? 请写出详细的解题步骤
【单选题】The research team decided to use an underwater saw to cut the ______ ship into sections before lifting it up.
【简答题】举例说明下列各命题是错误的: (1)若向量组a1,a2,…,am是线性相关的,则a1可由a2,…,am线性表示. (2)若有不全为零的数λ1,λ2,…,λm,使 λ1a1+λ2a2+…+λmam+λ1b1+λ2b2+…+λmbm=0成立,那么,a1,a2,…,am线性相关;b1,b2,…,bm也线性相关. (3)若只有当λ1,…,λm全为零时,等式 λ1a1+…+λmam+λ1b1+…+λmbm=...
【简答题】The ship was cut into several pieces in the accident.
【简答题】假设一信道带宽为4kHz,信道若要达到24kb/s的传输速率,问: (1)按奈奎斯特公式,需要( )个电平表示数据? (2)按香农公式,信道的信噪比是( )倍?
【单选题】Gas turbines differ from steam turbines in that ______.
A.
steam rather than gas is used to turn a shaft
B.
vapor rather than gas is used to turn a shaft
C.
the former uses gas to turn a shaft
D.
the latter uses gas to turn a shaft