Question

Look,someone______(clean)the classroom over there.填什么？

Look,the pumpkin______(turn)into a lantern.还有这个

Answer 1

第一个很容易，由look决定用现在进行时，也就是is cleaning即可。
第二题有难度，你必须认识所有单词，否则做不到。
1. pumpkin是南瓜， lantern是灯笼。
2. 应该用现在完成时，表示南瓜已经变成灯笼了。但南瓜与变之间不是施动关系，所以必须用被动。因此，必须填has been turned。

Answer 2

填写如下：
1). Look, someone is cleaning the classroom over there.
2). Look, the pumpkin has been turned into a lantern.

Answer 3

前者填have cleaned;后者填have turned。