用动词ing改写下列句子

动词 ing
你们老师要求你们做什么?练习进行时态,还是分词结构,或者是动名词?
进行时态：
I'm finishing my homework.
Carl bought a new cell phone.Now he has been receiving a lot of uesless short messages.
分词结构：
Having homework to do,I'll have to finish it today.
Having bought a new cell phone,he has received a lot of uesless short messages.
动名词：
I focused on finishing the homework.
Carl bought a new cell phone.Now he has to deal with deleting uesless short messages.
再问： 非谓语动词 第一句改finish一词 第二句用end up改写
再答： I worked on finishing my homework. Carl bought a new cell phone. He ended up receiving a lot of uesless short message.