A:Such challenging is the task; take to
B:So challenging is the task; take o
C:How challenging is the task; take u
D:The task is such challenging; take i
He used to _____ in a village, but now he has been used to _____ in the big city.
彩色电视机呈现出的各种颜色都是由三种色光混合而成的,这三种颜色是( )
减少“温室气体”排放量的措施,不正确的是 ( )
视力检测时要求被测的人与视力表的距离为5m.如图所示,视力表与平面镜的距离是3m.为满足测量要求,人与平面镜的距离应为( )