

1. (A)Plants and animals (B)live in the sea sank (C)to the seabed (D)when they died.
2. How (A)much times (B)did Rich and Jennifer have to do the experiment before they (C)obtained the results they had (D)been expecting .
3. We should put (A)people first and (B)save people's (C)lives is still the top priority of (D)our relief work
4. scientists and economists (A)believe that human beings (B)can never (C)use away all the (D)mineral resources on Earth
2. How (A)much times (B)did Rich and Jennifer have to do the experiment before they (C)obtained the results they had (D)been expecting .
3. We should put (A)people first and (B)save people's (C)lives is still the top priority of (D)our relief work
4. scientists and economists (A)believe that human beings (B)can never (C)use away all the (D)mineral resources on Earth