I wonder ______ you said to him before he came.

Now the air in our hometown is ___________ than it was before. Something must be done.

You should study _____ a test _____ reading the textbook. [ ]

Let’s look at the bag. Can you see _____“s” on the corner of_____ bag?

In the dark street, there wasn’t a single person _____ she could ask for help. [ ]