fix some typos found by Alexandra Kos

modules/doc/intro-01.rst

@@ -24,7 +24,7 @@ To load a PDB file, simply type
    fragment=io.LoadPDB('/path/to/examples/code_fragments/entity/fragment.pdb')
 
 This will load the fragment from the specified file 'fragment.pdb' and store the 
-result in fragment.  The :func:`~ost.io.LoadPDB` has many option, which, for 
+result in fragment.  The :func:`~ost.io.LoadPDB` has many options, which, for
 simplicity will not be discussed here. If you want to know more about the 
 function, type:
 

modules/mol/base/doc/query.rst

@@ -18,7 +18,7 @@ selections in a convenient way. Selections are carried out mainly by calling the
 
   arginines=model.Select('rname=ARG')
 
-A simple selection query (called a predicate) consists in a property (here, 
+A simple selection query (called a predicate) consists of a property (here,
 `rname`), a comparison operator (here, `=`) and an argument (here, `ARG`).  The 
 return value of a call to the :meth:`EntityHandle.Select` method is always an 
 :class:`EntityView`. The :class:`EntityView` always contains a full hierarchy of 

modules/seq/base/doc/seq.rst

@@ -17,10 +17,11 @@ Attaching Structures to Sequences
 --------------------------------------------------------------------------------
 
 
-Being a structural biology framework, it is not surprising that the sequence 
-classes have been designed to work together with structural data. Each sequence 
-can have an attached :class:`~mol.EntityView` allowing for fast mapping between 
-residues in the entity view and position in the sequence. 
+As OpenStructure is a computational structural biology framework, it is not
+surprising that the sequence classes have been designed to work together with
+structural data. Each sequence can have an attached :class:`~mol.EntityView`
+allowing for fast mapping between residues in the entity view and position in
+the sequence.
 
 .. _sequence-offset: