It is said that potato chips ___ by mistake about a hundred years ago. （ ）
| A．invent | B．invented | C．are invented | D．were invented |
January lst is _________ New Year’s Day. ( )
| A．called | B．call | C．calling |
She shouldn’t climb the fence. It is not . （ ）
| A．allowing | B．allows | C．allowed | D．allow |
Guangzhou is also ______ "city of flowers". ( )
| A．call | B．called | C．calling | D．calls |