[单项选择]适宜于作业地点相对固定且作业量相对固定场合的是（）起重机。
A. 塔式
B. 履带式
C. 轮胎式
D. 汽车式

{{B}}The Right Amount of Energy{{/B}}
We all enjoy being around people with energy. They inspire us. They are stimulating, fun, and uplifting. An energetic person has passion in his voice, a bounce in his step, and a smile on his face. Energy makes a person likable, and likability is a key ingredient in persuasive communications. Many business professionals underestimate the energy level required to generate enthusiasm among their listeners. But electrifying speakers bring it. They have an energy that is several levels higher than the people they are attempting to influence.
Most business professionals could use an energy boost for public speaking situations such as Webinars, podcasts, staff meetings, conference calls, and television and radio interviews. Each of these opportunities requires a higher level of energy than would normally be appropriate if you were just chatting to someone in the hallw
A. Because he has fun and it shows.
B. Because he doesn’t smile as much as he should during presentations.
C. Because he is very humorous.
D. Because he is famous.