Not until I began to work ________ how much time I had wasted[ ]

What a table! I’ve never seen such a thing before. It is____it is long.[ ]

Have you found a good method to solve the problem—No, I haven’t worked it out

I’m sorry I’m late. I got held up in the traffic on my way here.– ________ .

This is a very interesting book．I’ll buy it，．