Many kinds of animals are believed to have _________ from the earth A. withdrawn B.vanished C.found D.hung 7.The engineers in this lab spent several weeks _______ their plans for the new bicycle. A. counting B.stripping C.elaborating D.casting 8.Pine trees are usually believed to _______ cold weather. A. guard B.accomplish C.roar D.endure 9.Free medical service is _______ to nearly all the college students in China. A. favorite B.available C.convenient D.average 10.After working for twenty hours without any rest, the doctors were _______. A. exhausted B.mounted C.wrapped D.restored