Teams are required for most engineering projects．Although some small hardware or software products can be developed by individuals,the scale and complexity of modem systems is such,and the demand for short schedules so great,that it is no longer（ ）for one person to do most engineering jobs．Systems development is a team（ ）,and the effectiveness of the team largely determines the（ ）of the engineermg．Development teams often behave much like baseball or basketball teams．Even though they may have multiple specialties,all the members work toward（请作答此空）．However,on systems maintenance and enhancement teams,the engineers often work relatively independently,much like wrestling and track teams．A team is（ ）just a group of people who happen to work together．Teamwork takes practice and it involves special skills．Teams require common processes;they need agreed-upon goals;and they need effective guidance and leadership．The methods for guiding and leading such teams are well known,but they are not obvious．