He had begun to become familiar with North America while teaching in Mexico in the 1950 's and continued his education during an extended visit to Canada in 1969 and 1970 and to California in 1970 .
North America /location/location/contains Mexico
North America /location/location/contains Canada
PRP VBD VBN TO VB JJ IN NNP NNP IN NN IN NNP IN DT CD POS CC VBD PRP$ NN IN DT JJ NN TO NNP IN CD CC CD CC TO NNP IN CD .
North America
LOCATION
Mexico
LOCATION
/location/location/contains
North America
LOCATION
Canada
LOCATION
/location/location/contains