这个比较句型如何理解?their curiosity were excited when he would give o

这个比较句型如何理解?
their curiosity were excited when he would give on other reason for not coming to school earlier,or staying after school,than that he was "wanted at home"
这个than用来比较什么?when后面的从句和that后面的从句,还是earlier和that后面的从句
give no other reason 而不是on other reason
their curiosity were excited when he would give no other reason.
he did not come to school earlier,or stay after school,than he was wanted at home.
前面一句是主句，后面一句是分句。than后面的that是由he would give no other reason引起的。than前面是for后面用that