2.21.3 Can you answer these questions?

2.21.3.1 Coordinate Transformation for labeling with PGF-Plot
2.21.3.2 Can one use \stanza within a quote environment?
2.21.3.3 \write at the beginning of a table cell adds spurious vertical space

Can you answer these?

2.21.3.1 Coordinate Transformation for labeling with PGF-Plot

http://tex.stackexchange.com/questions/312117/coordinate-transformation-for-labeling-with-pgf-plot

Difficulty with drawing the right coordinates 
I use pgfplots to draw a set of data points, fit them with gnuplot and then find the intersection points between the linear fits and a vertical bar. Now  ...
 
- asked by Arne H. 3votes
2.21.3.2 Can one use \stanza within a quote environment?

http://tex.stackexchange.com/questions/312668/can-one-use-stanza-within-a-quote-environment

In the following example it can be seen that the line numbering is broken by the quote environment around the verse: 
\documentclass[article,12pt,a4paper]{memoir} 
\usepackage{lipsum} 
...
                                                                                  

                                                                                  
 
- asked by muk.li 2votes
2.21.3.3 \write at the beginning of a table cell adds spurious vertical space

http://tex.stackexchange.com/questions/312480/write-at-the-beginning-of-a-table-cell-adds-spurious-vertical-space

If a tabular column of type p (or a few others such as tabularx's X) starts with a write, this inserts some vertical space. MWE: 
\documentclass{article} 
%\usepackage{array} 
...
 
- asked by Gilles 3votes