继电器构成的控制系统,如果()或工艺发生变化,就必须重新设计,并改变硬件机构。
A.生产任务
B.气候条件
C.地理条件
D.大气压力
参考答案:A
Scientists observe ___ making the most of our senses when we are young can keep us healthy later on in life.
A.if
B.what
C.that
D.When
简述客户服务员工的组成与作用。