this factory has been open for twenty years.为什么是open 而不是opened

How long has this factory been open这句话转变成这样可以吗How long has been factory open Mr Smith has worked in this factory since he ( )to China A.has moved B.moved 要详解This factory ( )for twenty years.A.has opened B.has openC.has been poen D.has been popened My mother has worked in this factory 2 years.My mother has worked in this factory _____ 2 years.(A)about (B)for (C)in (D)since Mr Green has worked in this factory since 1998.since 1998.对它提问 this factory has been open for twenty years.为什么是open 而不是opened The Blacks ___ in this factory since 1998 A has worked B has come C have been Dhave arrived I wonder how long ago this radio factory-----a has begun b begins c began d has started Our factory has five _____workrs You should visit this part of the country when ___ A. spring will com B. spring comes C. It has bee how long this factory (开办) The problem (whether) this material can be used in our factory has not been solved.这是什么从句? He;s worked in this factory for many years ------ he?A.has B.hasn't C.is D.isn't Modern machinery __________ been installed in this newly ________ built factory.A.has B.have C.had D.is The（ ）production of engines in our factory has doubled this year.A.manualB.annualC.amountD.alike The factory has made more cars this year-there has been an increase in（ ）A .product B.produce C.production D.products为什么不选别的? The factory has made more cars this year—there has been an increase in _.A product B produce c.production Dproducts The factory has made more cars this year—there has been an increase in _.A product B produce c.production Dproducts