The engineers in this lab spent several weeks _______their plans for the new bicycle.
C
暂无解析
Heworksinouruniversityasavisiting_______,notasaformalfacultymember.
Whenyoufillintheapplicationform,pleaseuseyour_______addresssothatwecancontactyoueasilylater.
Thisriverissobigthatitisimpossibletobuilda_______underitwithoutmoderntechnology.