【We are working on a farm these days Mary's par】

问题补充：

We are working on a farm these days Marys parents drink tea after dinner两句区别

答案：

We are working on a farm these days

是说这些天正在进行的活动.

Marys parents drink tea after dinner

是说玛丽父母的一种习惯,所以用一般现在时.