摘要： suggest+名词、动名词短语、句子 suggest后面跟的是建议的事情，具有名词的特性。 比如： I suggest this method. I suggest trying once again. I suggest we have dinner now. we have dinner 这个 阅读全文

摘要： A=[1 2 3;4 5 6]; 法1：sum(A(:)); 法2：sum(A,'all'); 法3：sum(sum(a)) sum(a)是列求和sum(a,2)是行求和一般就是double型的，要是全矩阵求和，sum(sum(a)) 阅读全文