A:It
B:There
C:Thi
D:That
地壳中含量最多的元素是( )
____ He's my brother.
____ Who's that boy?
____ Yes, she is.
____ Is she your mother?
____ No, he isn't. He's my teacher.
____ Is he your father?
解方程
①8x÷0.7=8;
② 17 m+ 14 = 14 m;
③0.4:x=(1+ 18 ):5.
计算(9.6)0+lg25+lg4+7log72