He says that more students seem to make complaints might be due simplyomplaints 那么mig

He says that more students seem to make complaints might be due simplyomplaints 那么mig
He says that more students seem to make complaints might be due simply to the fact that universities are getting better at dealing with them 请帮助我分析这个句子的成份.he says 为主句,fact 后接个同位语从句,但says 后的that 引导宾主从句到complaints 那么might be 是什么从句怎么没引导词?seem是不及物动词要接宾语需加介词,但介词后只能接名词呀,看到的seem to 都是接动词原形怎么解释?