$ mongoexport --version
mongoexport version: r3.2.7
git version: 2214d4d6561574f962c1dc72fefce4fe11843023
cat foo.json
{"_id":{"$oid":"57605d5dc3d5a2429db0bce8"},"signup":{"$date":"2010-07-31T14:17:27.000Z"},"points":990061,"name":"Nick"}
{"_id":{"$oid":"57605d5dc3d5a2429db0bce9"},"signup":{"$date":"2010-06-02T00:21:35.000Z"},"points":291770,"name":"Ophelia"}
{"_id":{"$oid":"57605d5dc3d5a2429db0bcea"},"signup":{"$date":"2008-03-28T07:43:53.000Z"},"points":232650,"name":"Nick"}
$ mongoimport --drop -d test -c people foo.json
2016-06-14T16:30:26.683-0400	connected to: localhost
2016-06-14T16:30:26.684-0400	dropping: test.people
2016-06-14T16:30:26.849-0400	imported 3 documents
$ mongoexport -d test -c people --fields "name,points"
2016-06-14T16:30:38.564-0400	connected to: localhost
{"_id":{"$oid":"57605d5dc3d5a2429db0bcea"},"points":232650,"name":"Nick"}
{"_id":{"$oid":"57605d5dc3d5a2429db0bce8"},"points":990061,"name":"Nick"}
{"_id":{"$oid":"57605d5dc3d5a2429db0bce9"},"points":291770,"name":"Ophelia"}