If_____litters, our world will be more b...

—Can the plane fly _____ the Atlantic Ocean?

—Yes,but it needs to go_____the clouds for hours．

A．across,throughB．through, across

C．across,acrossD．through, through

—Can you tell me _____when the teacher came into the classroom?

—Sorry,I don’t know．

A．what were the students doing

B．what are the students doing

C．what the students were doing

D．what the students are doing

The teacher said that  _____  of the boys would take part in the fashion show．

A．two thirdB．three fives

C．three quartersD．three fifth

—______ did your sister leave China?

—She______ for three years ．

A．When, has leftB．When ,has been away

C．How long,has leftD．How long,has been away

“Don’t _____ to strangers on your way home．” Mother often_____ to me．

A．speak,tells

B．speak, says

C．talk, speaks

D．talk,tells