What statements are true? SQL is never used in NoSQL systems. SQL is sometimes used in NoSQL systems. Low-level query languages are often used in NoSQL systems. NoSQL data stores may be unstructured or semi-structured. Aggregates are not used in NoSQL stores. ACID-properties are always ensured in NoSQL systems. Eventual consistency is a property typical of NoSQL systems. Vertical scaling refers to adding more resources to the existing servers. What statements describe typical NoSQL systems? Stores were initially developed as single- server systems. Data distribution is done at the application level. MapReduce is used. Data replication is done at the application level. Data sharding is used. Data replication is used