The past two years ________ a sharp rise in oil price, which adds to the burden of auto transportation industry.   

Your phone ______ for several minutes now. Why don’t you answer it?

I can’t finish the experiment by myself, so the honor____ to all the members in our team.

—When did you have your school trip?—______.

Walmart, which is one of the largest American supermarket chains,         some of its store open 24 hours on Mondays through Saturdays.