请帮忙分析句子的结构,哪是主谓宾,that在句子中充什么成分?that是不是指the dogwood trees?可以去掉吗

Outside,状语
the late afternoon sun 主语
slanted down谓语
in the yard,状语
throwing into gleamingbrightness the dogwood trees that were solid masses of white blossoms against the background of new green.分词短语作伴随状语
that weresolid masses of white blossoms against the background of new green由that引导的定语从句,修饰 the dogwood trees, that 是指the dogwood trees,在这里不能去掉,因为that在定语从句中充当主语,作宾语的关系词才可以省略.throwing into 引导的是伴随状语从句，所以状语从句里面不能有句子，所以the dogwood trees 后面一定要加that,如果只有单独一句话：the dogwood trees that were solid masses of white blossoms against the background of new green，这个时候的that,就可以不要，是不是这样？先纠正一下throwing into gleamingbrightness the dogwood trees that were solid masses of white blossoms against the background of new green.是现在分词分词短语作伴随状语，不是状语从句。不是从句就不能是句子， that were solid masses of white blossoms against the background of new green 是定语从句就必须是句子。the dogwood trees that were solid masses of white blossoms against the background of new green 把它看成是一个简单句的话，那这个that就是多余的，句中就没主句了。