Ocean exploration is limited by
a. lack of technology
b. expense
c. favorable weather conditions
d. all of the above

Which phrase best describes the main goal of a human community

Planning along the natural slope of the land to reduce soil erosion is called

Cholera is a bacterial infection of the small intestine. vaccination provides protection against cholera. the cholera vaccine is made up of weakend form of the bacteria that causes cholera. the vaccine will stimulate blank production and elicit an immune response. if the infection occurs again, the bodynwill produce an even greater attack on thre bacteria because of blank.