选出最恰当的答案( )
A:To visit China.
B:To try something new.
C:To make friends.
D:To learn something easy.
走在路上,需遵守规则。影剧院里,需遵守规则。游乐场所,需遵守规则社会公共生活充满了规则。面对充满规则的公共生活,我们需要的态度是( )
如图是河蚌的结构示意图,请据图回答下列问题.
算式:____