【正确答案】正确答案：In the motorist's utterance, there are two types of speech acts performed, namely representative and directive, and as to the latter one, it is recognized as an indirect speech act, which is performed through the performance of the former one. Thus, by stating that his car needs new exhaust system, the motorist has in fact asked the mechanic to equip a new exhaust system for him. Similarly, in the mechanic's utterance, there are two types of speech acts performed; one is representative, the other commissive. The commissive speech act in fact is an indirect one since it is recognized through the performance of representative action. That is to say, by stating that he will be busy with another car all day, the mechanic has in fact told the motorist that he could not repair his car right away.