The wave structure of the polar front and the associated upper-tropospheric jet stream is caused by a. surface temperature contrasts between oceans and continents.
b. large-scale mountain ranges.
c. transient weather disturbances (mid-latitude low pressure systems).
d. (all of the above)

Ships can transit between the atlantic and pacific oceans using the canal.

Impressions of tropical swamp plants were observed on rocks in polar regions. the impressions were dark black imprints, which means the fossils are examples of ( 1 ) the fossils tell us that polar regions ( 2 ) ( 1 ) a. carbonization b. mineralization c. trace fossils ( 2 ) a. had tropical plants that can grow in ice b. might have had a diffierent climate in the past c. will have abundent vegitation

Which of the following is an example of a policy that may be implemented by a business that has trouble with employees using the internet for their own personal needs? a. all employees will have to take a safety training class. b. employees caught using the internet for personal needs will have to take a professional development class. c. personal interviews will be conducted to find out who is using the internet for personal needs. d. employees will be monitored, but nothing will happen if their employer catches them using the internet for personal needs.