北方常在早春播种后进行地膜覆盖，这是为了（ ）
A：增加空气
B：增加光照
C：提高温度
D：防止被虫蛀
“青山遮不住，毕竟东流去”蕴含新事物必然战胜旧事物的哲学道理。（ ）
There are ________ on the farm.
— Do you think it is going to rain tomorrow?— ___________. We are going camping tomorrow.
