| Rectangle Selection | 
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Allows selection in rectangle mode on mouse drag. | 
| Lasso Selection | 
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Allows selection in lasso mode on mouse drag. | 
| Structure Selection | 
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Allows selection in structure selection mode on mouse drag. With this selection mode, only whole fragments can be selected. | 
| Erase | 
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Removes all structures upon selection. | 
| Undo | 
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Reverses the last command or the last entry you typed. | 
| Redo | 
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Reverses the action of the last undo command. | 
| Cut | 
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Removes and copies the selection to the clipboard. | 
| Copy | 
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Copies the selection to the clipboard. | 
| Paste | 
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Inserts the contents of the clipboard at the location of the cursor, without replacing selection. | 
| Check Structure | 
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Checks and corrects chemical structures. See Structure Checker User's Guide for more information. | 
| Zoom In | 
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Increases the magnification of the canvas. | 
| Zoom Out | 
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Decreases the magnification of the canvas. | 
| Zoom Tool | 
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Changes the magnification of the canvas to a specific value.  It can also do autoscale using the following named values: All, Selection, Scaffold (only when an R-group is defined on the canvas), and R-group (only when an R-group is defined on the canvas) | 
| Help Contents | 
  | 
Shows MarvinSketch User's Guide. |