My teacher was so angry at _______________ he walked out of the office without a word.

下列各句中，没有语病的一句是

One of our rules is that every student _______ wear school uniform while at school.

Many firms give away small quantities of theirproductions as _______ so that people can try them before buying.

My sister was very afraid all the way because it was the first time she ______ a car. [ ]