Theengineersinthislabspentseveralweeks_______theirplansforthenewbicycle.
A、countingWecannot_______allthemagazinestogether.
Thismorningintheclass,ourteacherlosthis______atlastbecausehecouldnotstandanymore.
Whenmakingmoderncameras,peoplebeganto_______plasticsformetal.
Thisriverformsanatural_______betweenChinaandKorea.
Afterworkingfortwentyhourswithoutanyrest,thedoctorswere_______.
