a) The populations of the world is growing. Will we be able to grow enough food?
b) One reason GM crops are controversial is that we do not know what the health risks may be.
c) Scientists want to recreate the wooly mammoth.
d)Is it ethical to clone a human being?
8.-Complete these sentences with the verbs in parentheses in the correct tense
a) When he sometimes uses (use) the internet to find information?
b) When did scientists clone the first animal ? (clone)
c) The woolly mammoth not existed (not exist) for thousands of years now.
d) Will we be able to (be able to ) stop people from getting old in the future.?
e) Will scientists are do (do) enough research about the effects of GM crops?