Usages of ga
B: This one is yours.
Note: the subject marker が is more appropriate than は in this context. The subject of the sentence is たくさんのユダヤ人 (many Jewish people), and in this case, が is typically used because it is introducing new, non-contrastive information.
Literally: there is no way of doing.
ushiro mo iriguchi ga arimasu.
なあ is used here to both express reflectiveness and seek confirmation
ない is the negative form of ある, and なくて is the connective form of ない
いない is the negative form of いる, and いなくて is the connective form of いない
The particle combination には is often used to emphasize the topic, especially when discussing existence, characteristics, or attributes related to that topic. It can be translated as as for or regarding, but often it's simply used to stress the topic being discussed.
Note how we're using の here instead of using the word 石鹸 twice.
tenki ga ii to, sanpo ni ikimasu.
You cannot use と here, as the consequence is neither habitual nor uncontrollable.
benkyoushitara, toshokan ga shizuka desu.
The たら form is ungrammatical here, because the library is quiet is not something that happens after you're going to study.
Both 人気 が ある and 人気 です are correct translations for to be popular.
The particle で is used here because the fire is an event and not a static object.