--- Where are the students ? How could they keep us waiting for so long? --- They started an hour ago and they____ be here in fifteen minutes, I think.
27. The boy gathered all his _____ to stand up.
26. We were all waiting for you. You _____ for the seaside by yourself without leaving a message.
25. When a person wants to operate the computer, _____ read instructions first.
24. _____ many other scientists, Albert Einstein enjoyed music besides scientific research work.
23. He did as much as he _____ her.