1.electric cars don't pollute the environment because they don't have_____

A.roof       B.wheels       C.pedals        D.fumes

2we_____probably travel to the moon in twenty years
A.do             B.did                    C.are                   D.will

3.they launched a rocket to the______venus

A.planet             B.star                    C.sky                   D.earth

4a teleporter makes you disappear at a place and then_____in another place

A..reduce            B.redo              C.review                   D.reaper

5a bamboo-copter is______to use.you just put it on and fly away

A.difficult                        B.easy                         C.interesting                         D.self-balancing

6the demand for cars that are______on fuel increasing

A.convenient                        B.economical                         C.comfortable                         D.eco-friendly