第一个的同义句是：
He said hello to us without looking at us.
look要用ing形式.
第二个：
How large can televisions be now?
“现在电视可以是多大的?”
第三个：
同义句是：
Billy was (not)(thin)(enough)(to)get into the hole.
"贝利不够瘦,钻不进去那个洞."
Billy was (too)(fat)(to)get into the hole.
“贝利太胖了,进不去那个洞.‘
【公益慈善翻译团】真诚为您解答!