单项选择题 The author most likely mentions the physical appearance of the impoverished child in the last paragraph in order to: A、criticize a social upbringing that would allow a child to suffer in such a way. B、contrast the poverty of the second child with the privilege of the first. C、intensify the reader's sympathetic reaction toward the child. D、identify the cause of the child's poverty. 无解析

单项选择题 立体裁剪起源于哪里？ A、欧洲 B、亚洲 C、非洲 D、美洲

单项选择题 若x表示参数向量，间接平差的法方程可以写为下列哪种形式（ ） A、 B、 C、 D、