Question

The United Kingdom (1) _________ the first country in the world to allow scientists to create human-animal embryos for research purposes. The research (2) _________ transferring nuclei containing DNA from human cells to animal eggs that (3) _________ nearly all their genetic information removed. The resulting embryos (4) _________, therefore, mostly human, with a small animal component.

1. (a) became; (b) has become; (c) have become; (d) become 2. (a) involve; (b) involves; (c) is involving; (d) has involved 3. (a) have; (b) are; (c) have had (d) had 4. (a) is; (b) are; (c) have; (d) have been​

Answer 1

1)HAS BECOME

2) INVOLVES

3)HAD

4)HAVE BEEN

Answer 2

Answer:

below

Explanation:

a) became

b) involves

c)have

d)have been