Dr Black comes from either Oxford or Cambridge. I can't remember _____.
----Whose advice do you think I should take? ----________.
Leaves are found _______ all kinds of trees, but they differ greatly ________ size and shape.
To save class time, our teacher has ________ students do half of the exercises in class and complete the other half for our homework.
Darwin counted 225 flowering plants, ________ he collected and brought home 193.
The government has taken some measures to reconstruct the earthquake-hit areas, but it must be some time ________ everything returns to normal.