Segway is a _______ electric vehicle.

      A. one-wheeled              B. two-wheeled                    C. three-wheeled       D. four-wheeled

• one-wheeled

• two-wheeled           

• three-wheeled

• four-wheeled

They _______ testing solar-powered ships many years ago.

      A. begin                         B. begins                              C. began       D. beginning

• begin

• begins

• began

• beginning

A sky safety system will help everyone _______ traffic jams.

      A. stop                            B. affect                               C. avoid       D. get

• stop

• affect

• avoid

• get

You won't have to worry _______ bad weather when you travel in hyperloops.

      A. about                         B. for                                    C. on       D. in

• about

• for

• on

• in

Electric cars don't pollute the environment because they don't have _______.

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

• roof                           

• wheels                            

• pedals      

• fumes

We _______ probably travel to the Moon in twenty years.

      A. do                              B. did                                   C. are       D. will

• do                             

• did

• are

• will

We _______ know our exam results in two days.

      A. be                              B. did                                   C. will       D. do

• be                             

• did

• will      

• do

People _______ much faster thanks to super cars in ten years.

      A. travel                         B. travels                              C. will travel       D. travelled

• travel

• travels

• will travel

• travelled

I'm afraid I _______ able to attend your workshop tomorrow.

      A. won't be                     B. isn't                                  C. wasn't       D. weren't

• won't be        

• isn't

• wasn't

• weren't

My uncle often _______ us on Tet holidays.

      A. will visit                    B. is visiting                         C. visits       D. visited

• will visit         

• is visiting    

• visits

• visited