A:was; receive
B:should be; received
C:be; should receive
D:is; should receive
山脉构成地形的骨架.下列山脉中,该山脉以东为平原,以西为高原的山脉是( )
10100 千米=10%千米
观察下列各式:a+b=1,a2+b2=3,a3+b3=4,a4+b4=7,a5+b5=11,…,则a10+b10=( )