Fix some errors in notes

2-2-cuda.md

@@ -83,11 +83,7 @@
         ...
     }
     ```
-- A complete example:
-
-    ```c
-
-    ```
+- A complete example: see code in `./assets/code/`
 
 ### Block Hierarchy
 

4-3-NOSQL.md

@@ -152,9 +152,6 @@
 - Advantages:
     - Fast response to clients
     - Off-loading of database servers
-    - Counterpart of Eventual consistency
-    - All read must return data from latest write
-    - Very hard to achieve with high availability and high partition tolerance
 
 ### Separating Reads from Writes