下列各句中，表达得体的一句是

My sister and I inthe room, now.

At one point I made up my mind to talk to UncleSam. Then I changed my mind, ____ that he could do nothing to help.

When I passed the river, I saw some children ______ on the sand.

Don’t try to cheat the taxman (税务人员); you’ll never ________it.