15.You may ________ the textbook if you don’t know the answer to the question.
special
touch
I don't want _______like I' m speaking ill of anybody, but the manager's plan is unfair.
He tried his best to solve the problem, _______difficult it was. A. however B. no matter C. whateverD although
I'm moving to the countryside because the air there is much fresher than________ in the city.