看图写话。
Bob is busy on Monday and Wednesday. He swims on Monday. He draws on Wednesday.
Mary is busy on Tuesday and Thursday. She plays the piano on Tuesday. She plays football on Thursday.
即便是沙漠中的植物,吸收的水也大多通过气孔散失了,散失的方式为( )
维C泡腾片可增强机体抵抗力,用于预防和治疗各种急、慢性传染性疾病或其他疾病.
(1)维生素C所属的物质类别是____ (填“有机物”或“无机物”)
(2)这种片剂加入水后,会冒出气泡.原因是____ .
(3)向维C泡腾片溶液中滴加石蕊试液,溶液变红,说明溶液显____性.
在-52、2、-4、﹣π、3.010010001…(每两个1之间依次增加一个0)五个数中,无理数有____个.