选择最佳应答语( )
A:You are welcome.
B:Go ahead,please.
C:Sure,no problem.
The writer mentions birds and frogs to .
Everyone should keep discipline and you are no____ (例外).
有一个长方体玻璃缸,长3分米,宽2分米。放入一块不规则的石头后水深1.5分米,捞出这块石头后,水面下降了0.5分米。这块石头的体积是多少?
读大河流域文明发祥地图,完成相关题目。