脊髓灰质炎密切接触者应严密观察()
A.7天
B.10天
C.15天
D.20天
E.30天
参考答案:D
Only when your identity has been checked__________.
A.you are allowed to come in
B.You will be allowed to come in
C.will you allow to come in
D.will you be allowed to come in
随着城市发展,城市郊区的农业结构将发生变化。下列土地利用类型在农业用地中的比重
最可能降低的是( )
A.稻田
B.鱼塘
C.果园
D.菜地花圃