If you____(to drive) along the river bank it___(to be) twenty miles out of your way. If you___(to take ) your mobile phone into class,it____(must) be turned off. We ___(not use) calculators when we ___(write)test. If you___(to push) this button,the volume ___(to increase). If you ___(to close) the door,it ___(to lock)automatically. I___(to wear) my old boots when I ___(to work) .when I ___(to cook)salads , I ___(to use) only olive oil. When I ___(to concentrate), please ___(not to make) so much noise. Unless prices ___(to rise),it___(not to be) a good investment. Unless someone __(to ask) you politely,___(to refuse) to do anything.