问题
选择题
—What's this in English?
—______.[ ]
A. Yes ,it is
B. No, I don't
C. It's an apple
D. A-P-P-L-E
答案
答案：C
搜题请搜索小程序“爱下问搜题”
—What's this in English?
—______.[ ]
A. Yes ,it is
B. No, I don't
C. It's an apple
D. A-P-P-L-E
答案：C
所确定的函数z=z(x，y)在点(1，0，-1)处的全微分dz=______．