十分健全 meaning in English

as sound as a bell

He's not quite composmentis .
他的精神不十分健全。
The financial system is robust
金融体系亦十分健全。
" well , sir , by the help of two signs , with which i will acquaint you presently , you may ascertain with perfect certainty that my grandfather is still in the full possession of all his mental faculties
“哦，阁下，仅从两个表示上您就可以完全确定我祖父的脑力依旧是十分健全的。