She opened the door quietly not to __________ (打扰）the sleeping boy.
There is no c______ between the two incidents.
It is only the a______ of these goals that will finally bring lasting peace.
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)