青藏高原上独特的地表景观是( )
A:林海茫茫
B:沟壑纵横
C:雪山连绵
D:黄沙遍野
Around the AD 1000's, a man ____ (call) Bi Sheng in China invented a more flexible (灵活的) system of printing.
已知,抛物线y=ax2+bx+c(a≠0)经过原点,顶点为A(h,k)(h≠0).
型号
xx-xx
额定容量(米3)
3×10-3
额定电压(伏)
220
额定功率(瓦)
1000