The population decreased from the 1840s until about 1970, largely because of ______.
A.a low birth rate B.a high death rate C.a low employment rate D.a high emigration rate正确答案D
The population decreased from the 1840s until about 1970, largely because of ______.
A.a low birth rate B.a high death rate C.a low employment rate D.a high emigration rate正确答案D