How can foreign pieces of DNA be transferred into organisms? A) by restriction enzymes

B) by vectors

C) by carrier enzymes

D) by test crosses

B) Vectors

Explanation:

They are also called carriers.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

i don't know. if i were you, i would search it up online : d