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8th Class Chhattisgarh NMMS 2020 – 2021 for Class VIII – Answer Key (Released) Rajasthan NMMS 2021 for Class 8 – Application Form, Eligibility, Syllabus, Notification. Download 8th Class NCERT Book PDF. NCERT books for Class 8 are published by the National Council of Educational Research and Training (NCERT). These books are also responsible for setting the academic standard of Class 8 of the CBSE board. 8th Class Model Paper PDF 2021 – CBSE. With reference to model papers, you can revise your whole chunk of syllabus within time. 8th Class Model Papers is designed in such a way, thus ensuring you carry out entire syllabus revision in an efficient way. Apart, this VIII Class Model Paper 2021 will make you familiar with all sort of questions.

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DHL's deliveries in the Los Angeles area are going to get a little greener in time for the holiday rush. The international courier company is deploying four Class 8 trucks to the city, built for it by BYD Motors, which it will use to haul cargo between its hub at Los Angeles International Airport and its local service centers.

'By implementing these electric trucks, we will prevent more than 300 metric tons of greenhouse gas emissions from entering the atmosphere per year, as we continue to grow and enhance our clean pick-up and delivery solutions,' said Greg Hewitt, CEO of DHL Express US.

'The introduction of these efficient electric trucks is a huge step forward, not only toward achieving our own clean transport goals, but also California’s ambitious goals on the adoption of zero-emission vehicles,' Hewitt said.


Although not every use of a heavy truck lends itself well to electrification, there's no denying that for applications that involve short-haul routes like port drayage, school buses, and garbage collection, it's a no-brainer.

Indeed, in the face of continuing inaction or even actively destructive policy at the federal level, the state is moving ahead with decarbonizing transportation within its borders. On Tuesday, the California Air Resources Board announced a new state-wide incentive called the California Clean Fuel Reward. Together with utility companies, CARB will give buyers of new battery-electric vehicles and plug-in hybrid EVs up to $1,500, separate to any other state or federal incentives.

An object that maps keys to values. A map cannot contain duplicate keys; each key can map to at most one value.

This interface takes the place of the Dictionary class, which was a totally abstract class rather than an interface.

The Map interface provides three collection views, which allow a map's contents to be viewed as a set of keys, collection of values, or set of key-value mappings. The order of a map is defined as the order in which the iterators on the map's collection views return their elements. Some map implementations, like the TreeMap class, make specific guarantees as to their order; others, like the HashMap class, do not.

Note: great care must be exercised if mutable objects are used as map keys. The behavior of a map is not specified if the value of an object is changed in a manner that affects equals comparisons while the object is a key in the map. A special case of this prohibition is that it is not permissible for a map to contain itself as a key. While it is permissible for a map to contain itself as a value, extreme caution is advised: the equals and hashCode methods are no longer well defined on such a map.

All general-purpose map implementation classes should provide two 'standard' constructors: a void (no arguments) constructor which creates an empty map, and a constructor with a single argument of type Map, which creates a new map with the same key-value mappings as its argument. In effect, the latter constructor allows the user to copy any map, producing an equivalent map of the desired class. There is no way to enforce this recommendation (as interfaces cannot contain constructors) but all of the general-purpose map implementations in the JDK comply.

The 'destructive' methods contained in this interface, that is, the methods that modify the map on which they operate, are specified to throw UnsupportedOperationException if this map does not support the operation. If this is the case, these methods may, but are not required to, throw an UnsupportedOperationException if the invocation would have no effect on the map. For example, invoking the putAll(Map) method on an unmodifiable map may, but is not required to, throw the exception if the map whose mappings are to be 'superimposed' is empty.

Some map implementations have restrictions on the keys and values they may contain. For example, some implementations prohibit null keys and values, and some have restrictions on the types of their keys. Attempting to insert an ineligible key or value throws an unchecked exception, typically NullPointerException or ClassCastException. Attempting to query the presence of an ineligible key or value may throw an exception, or it may simply return false; some implementations will exhibit the former behavior and some will exhibit the latter. More generally, attempting an operation on an ineligible key or value whose completion would not result in the insertion of an ineligible element into the map may throw an exception or it may succeed, at the option of the implementation. Such exceptions are marked as 'optional' in the specification for this interface.

Many methods in Collections Framework interfaces are defined in terms of the equals method. For example, the specification for the containsKey(Object key) method says: 'returns true if and only if this map contains a mapping for a key k such that (keynull ? knull : key.equals(k)).' This specification should not be construed to imply that invoking Map.containsKey with a non-null argument key will cause key.equals(k) to be invoked for any key k. Implementations are free to implement optimizations whereby the equals invocation is avoided, for example, by first comparing the hash codes of the two keys. (The Object.hashCode() specification guarantees that two objects with unequal hash codes cannot be equal.) More generally, implementations of the various Collections Framework interfaces are free to take advantage of the specified behavior of underlying Object methods wherever the implementor deems it appropriate.

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Some map operations which perform recursive traversal of the map may fail with an exception for self-referential instances where the map directly or indirectly contains itself. This includes the clone(), equals(), hashCode() and toString() methods. Implementations may optionally handle the self-referential scenario, however most current implementations do not do so.

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This interface is a member of the Java Collections Framework.