由共轭复数的定义知,
复数z=2+i的共轭复数为:2-i,
故答案为:2-i.
81. ________is a kind of food made from milk curds.
A.Cheese
B.Sandwich
C.Cake
D.Cherry
滚动型或摇摆型支承的()应保持密封,不得有雨水、灰尘等进入罩内。
A、防护罩
B、支承环
C、排水管
D、渐变管