xiǎo shēng chū
progression from elementary school to junior high (abbr. for 小學生升入初中生|小学生升入初中生[xiao3 xue2 sheng1 sheng1 ru4 chu1 zhong1 sheng1])
小
xiǎo
small
升
shēng
to ascend; to rise (variant of 升[sheng1])
初
chū
at first