They use the same senses as we do and their feet and hands are similar toours,　　　chimpanzees still have opposable toes and can grasp things with their feet

_____ on the subject for half an hour, Liu Ying suddenly stopped. [ ]

It took me quite a while to ______ how to solve this problem.

Which would you like, coffee or cola— _________, thanks. I’d like a cup of tea.

___________ –Yes, I am.