Let’s clean the classroom, ________?

.—She must have gone back to the valley. —No, she_________. The entrance to it was nowhere to be found. 

(2013·江西南昌一模)Why ________ it get colder when we climb up a mountain? We are getting nearer to the sun!

If there were no exams and parents meetings, high school life __ much enjoyable.

“ Have you ever been to Beijing?”  “No, but I wish I________.”