Students in Grade Nine ____________a maths exam at this time yesterday．（ ）
A．takeB．are taking
C．were takingD．have taken
﹣﹣﹣Lucy，have you changed a mobile phone with 5 G？
﹣﹣﹣Yes，I think the mobile phone with 5 G can send videos much_______ than the one with 4 G.（ ）
A．fastB．fastest
C．the fastestD．faster
﹣﹣﹣Are these books_______？
﹣﹣﹣No，they're his.（ ）
A．yoursB．herC．ourD．their
﹣﹣﹣What did the teacher say just now？
﹣﹣﹣He told us________in the river.（ ）
A．swimB．swimming
C．not to swimD．not swim
﹣﹣﹣What' s your favorite_______ ，John？
﹣﹣﹣History.It is very interesting.（ ）
A．foodB．vegetableC．animalD．subject
William six books，and all of them are bestsellers.（ ）
A．will writeB．is writing
C．has writtenD．was writing