An increased concentration of carbon dioxide and certain other gases in the Earth’s atmosphere ______ global warming.
When you learn a foreign language, ________you must forget your own one.
Italians often approach others closely and are moreto touch them.
Everyone will have to ______ a test before they are admitted to the university.
--Haven’t seen you for ages! Where have you been, anywhere? --I _______ to New York City. I just got back.
A new_____to teaching English is being used here, and it has proven to be very helpful to the students.