French language Q&A Forum

It says to use MIEUX for a general statement with être about something or someone being fine/OK/better/the best. 

Can we say.... "C'est la mieux idée." ? [This/It is the best idea.]

Why/Why not?

Under “nous avons pu réinvestir les dons qui nous étaient parvenus”, the “voix passive” lesson is listed beneath it, and not the “plus que parfait” lesson. 

But isn’t it that case that this line is an example of plus que parfait, and not of voix passive?

This may seem like splitting hairs, but I find the listed lessons very useful even just from their titles, to guide my understanding of the grammar. 

Just to ask why it is "de conseils" , not "des conseils" ?

Is it because it is a continuation of "plein de" ?

I believe plein de is invariable, i.e. would never use des.

e.g. "plein de trucs" , "plein de choses"

Thanks

Paul.

In the sentence, "Il s'agit de l'un des plus grands bâtiments gothiques d'Europe, dont les fresques finement ouvragées vous laisseront bouche bée d'admiration.”, duquel,  referring to 'un', is not offered as a possibility.   Why not?