单项选择题 纱罗组织中，当绞经每改变一次左右位置，织入 ( )的纬纱。

单项选择题 （单选）以下关于滤液流率的说法，正确的是（）*

单项选择题 【单选题】A careful analysis of cellular components discovers short-lived RNA species in which an adenine nucleotide is found with three phosphodiester bonds (linked to the 2’, 3’, and 5’ carbons). This transient structure is formed during which of the following processes? A、mRNA cap formation B、C、 D、 E、SplB、mRNA polyadenylationC、Transcription of rRNAD、Transcription of microRNAsE、Splicing of hnRNA