He suggested that the method is popularized at once.suggested ,method,is popularized,at once哪个错了.

He suggested that the method is popularized at once.suggested ,method,is popularized,at once哪个错了.
He suggested that the method is popularized at once.suggested ,method,is popularized,at once
哪个错了.

He suggested that the method is popularized at once.suggested ,method,is popularized,at once哪个错了.
is popularized应该改成 should be popularized

is改为was，was popularized