______ a certain doubt among the parents as to the necessity of children's doing so much homework.
Let’s talk about the persons and the things ________ we can remember.
So far all cloned animals have suffered from some different serious disorders,________ dying soon after birth.
The students ________ are expected to pass.
Jim passed the driving test,________ surprised everybody in the office.
I want to use the same dictionary ________ was used yesterday.