问题
选择题
The man ____ you are going to make friends is my father’s neighbour.
A．with whom
B．when
C．to whom
D．which
答案
答案：A
搜题请搜索小程序“爱下问搜题”
The man ____ you are going to make friends is my father’s neighbour.
A．with whom
B．when
C．to whom
D．which
答案：A
(t)dt，其中函数φ具有二阶导数，ψ具有一阶导数，则必有______．