TD-SCDMA使用()和()两种调制方式。
参考答案:QPSK,8PSK
34. It is fairly common in Africa for _______ a group of musicians surrounded by others who also join in the performances.
A.there are
B.there being
C.there to be
D.there be
下列有关说法正确的是( )
A.CaCO3(s)═CaO(s)+CO2(g)室温下不能自发进行,说明该反应的△H<0
B.镀铜铁制品镀层受损后,铁制品比受损前更容易生锈
C.N2(g)+3H2(g)催化剂.高温高压2NH3(g)△H<0,其他条件不变时升高温度,反应速率V(H2)和氢气的平衡转化率均增大
D.水的离子积常数Kw随着温度的升高而增大,说明水的电离是放热反应