French language Q&A Forum

I got this question:

Cette pomme est bonne. - Oui, c'est _______.

I answered bon because I knew to use the masculine, but my question is why it's c'est in this case. I've read the relevant pages ("C'est" vs "Il/Elle est" to say it is/she is/he is in French and Standalone adjectives after c'est are always masculine) and my interpretation is that this would fall under 2b of "C'est" vs "Il/Elle est" to say it is/she is/he is in French: 

The pronunciation of 'tandis que' in this exercise has the 's' pronounced quite clearly (sounds like tandisse que). I wondered if this was an optional way to pronounce it, as I thought that the final 's' is usually silent in this word ? 

In France is “ Maison de retraite “ interchangeable with “Ephad”?

Is there any  distinction between a facility where aged people live together and do not need care and a facility where aged people need nursing care?

In your correction, you said that "nous avons aussi appris a changer une roue" rather than un pneu.  Une roue translates, as per my dictionary, to be "a wheel," while  "un pneu" is a tire.  I'm probably splitting hairs, but it is different to change a wheel than a tire; the wheel is the base on which the tire sits and would therefore be a much bigger job than changing the tire alone.  As I said, I'm splitting hairs, but want to know if in common parlance, the roue is changed when the pneu is flat.  Also, others have asked the other questions I had - about the use of plus-que-parfait (suggested but not actually used in the "correct" translation) and about the use of encore rather than toujours.  Thanks for your help.  It is greatly appreciated!

The rule concerning agreement of "tout" in different situations confuses me.  Why isn't it written "toute à l'heure" so that tout agrees with the gender of l'heure?  Thanks.

I found this explanation in Le Figaro but it does not explain why there is no agreement: https://www.lefigaro.fr/langue-francaise/expressions-francaises/2019/01/23/37003-20190123ARTFIG00047--toute-a-l-heure-ne-faites-plus-la-faute.php