Montags and Clarisse's realtionship is weird. If she had not died I think they would have become a lot closer throughout the book. Clarisse seemed to bring out a different side of Montag. They way she would ask him questions and make things for him.
JKS stands for Java KeyStore. It is a repository of certificates (signed public keys) and [private] keys. You can export a certificate stored in a JKS file into a certificate file. You can use the keytool utility found in Java distributions to maintain your JKS trust and key repositories.
.CER - Certificate file i.e. public ckey. You can convert from CER to JKS as you are only converting the public key. Both command line tools and API will allow you do that. I don't believe you can access the private key from JKS file even with password ( for the purpose of exporting). I could be wrong.