The best way to explore _______ countryside is on _______foot.
27. —— My goodness! I've just missed the train. —— That's too bad. I am sure you__________it, if you had hurried.
26. The pen I _______ I _______is on my desk, right under my nose.
25. He is one of the old scientists who ______nothing about his personal income and fame .
24. —— How about camping, just for a change?—— OK, ______ you want.
23. In face of failure, it is the most important to keep up good state of mind.