题目内容：
根据下列选项，回答题。Cargo Insurance is one of the most important consideration trades．To meet the
requirement of marine cargo teansportation，various kinds of marine risks can be covered under different insurance policies．The risks covered in1 coverage basically means that only total or constructive total loss of the whole consignment of cargo，but no partial loss or damage is recoverable from the insurer resulting from natural calamities，such as2 and flood．3 provides cover since loss and damage is recoverable from the insurer resulting from natural calamities．4 is the most widely used in the transport of marine cargo because it provides insurance against all risks of loss or damage to the cargo insured arising from external causes in the course of transit．But it does not cover risks of war， 5 ，and other special additional risks such as failure to delivery and import duty．
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