Question

The rest of the students______(plant)trees by the river now.

Answer 1

为你解答。
The rest of the students (are planting) trees by the river now.
其余的学生正在河边种树。
解释：the rest of the students，剩下的学生们，这里是可数名词的复数。

Answer 2

are planting。 先确定时态，因为有时间状语Now，所以为一般现在时，Students为复数，所以be动词用are。

Answer 3

The rest of the students are planting trees by the river now.
其余的学生现在正在河边种树。