He mended the mechanism, ___ (同时), she watched him.
Two thirds of the water ______ (have) been used but still two thirds of the people _____(be) short of fresh water.
The father as well as three children ______ skating on the frozen river in winter.(go)
Manny a student ______ failed in the exam. (have)
He who ______ not reach the Great Wall is not a true man. (do)
He is one of the teachers who ______ popular in our school. (be)