When keeping a laboratory notebook, a student should 1. always start every experiment where one left off and put the date and title in the margin.2. mark out any unused portion of the page to indicate the conclusion of the day's work if there is no additional work to be done with the experiment. 3. start every experiment on a new page with a date and title at the top. 4. avoid including any changes to the experimental procedure that may have been necessary and the reasons for the change.

2. mark out any unused portion of the page to indicate the conclusion of the day's work if there is no additional work to be done with the experiment.

3. start every experiment on a new page with a date and title at the top.                                            

Explanation:

A laboratory notebook is a mainly used as a working document in a research  work or an experiment. It is the first place where we record all the work, including the hypotheses, the experimental setup, calculations, data  and the early analysis.

In order to make a lab copy to start a new experiment, we should always start a new experiment in afresh page giving the date and the title of the experiment at the top. Also at the end of the experiment, we should mark the unused portion of the page in order to show the result of the day's experiments when there is no other additional work to be done.

rain should be the answer.