题目

Directions: Complete the following passage by using ONE word that best fits the context. Scholars and researchers have tried to discover what personality characteristics go along with success in intercultural experiences. Their findings have often been unclear or incomplete.  48   three characteristics stand out in their reports: patience, a sense of humor, and the awareness of being unclear. Patience, of course, is the ability to keep calm even  49  things do not go as one wants them to, or hopes they will,  50  has even been sure they will. A person with a sense of humor is   51 li如图所示，工人用动滑轮匀速竖直向上提升重480N的货物，他在4S内做了600J的功，货物上升了1m．求：（1）工人做功的功率是多大？（2）工人提升货物时，作用于绳子端点的拉力的大小．（3）动滑轮的机械效率是多大？