to search; investigate

dig into task, action

to travel into or through (a country etc) for the purpose of learning about it

investigate; survey

to make an effort to continue with, do, (especially difficult or tiring)

keep at; work hard

to refuse, in spite of argument, opposition, failure etc to make any change (in what one is doing, one's beliefs etc)

carry on, carry through

to search (a place) untidily and thoroughly

turn inside out in search; ravage

to go to or near (a place or area occupied by enemy forces) to learn about their position, strength etc

investigate; survey

to turn things over, move things about, while looking for something

ransack, search

to look for (a person, thing); try to find; to ask for (something)

look for

to struggle; to make great efforts

try for, exert oneself

of strive

try for, exert oneself