30. It is a good city for cycling because it is flat and ________is convenient for bikes.
| A．however | B．what’s more | C．therefore | D．Besides |
She________ for nearly two hours.
| A．kept talking | B．kept to talk | C．has kept talking | D．kept to talking |
Spring_______ after winter.
| A．comes | B．came | C．has come | D．had come |
—I hear some noise in the next room.
—Oh, yes. Your sister_______ there.
| A．cries | B．is crying | C．cried | D．was crying |
All the students__________ to plant trees and there’s nobody in the classroom.
| A．go | B．will go | C．have gone | D．wound go |
Stop! A little boy_________ the street.
| A．is crossing | B．crosses | C．crossed | D．has crossed |