Answer:
We do wear helmets when we bike together, as a rule.
Explanation:
Emphatic forms of verbs are used to emphasize what is expressed by the verb. This is accomplished by the use of the auxiliary verb <em>to do</em>. There are two emphatic tenses: the present and the past emphatic tense. Depending on the tense, a fitting form of the verb <em>to do</em> (<em>do/does</em> for present tense, <em>did </em>for past tense) is used together with the base form of the verb. For example:
<em>He does like reading.</em> (Instead of simply<em> He likes reading.</em>)
<em>He did do his homework</em>. (Instead of <em>He did his homework</em>.)
The same form is present in the sentence <em>We </em><u><em>d</em></u><u>o </u><em><u>wear </u></em><em>helmets when we bike together, as a rule.</em> (Instead of <em>We </em><u><em>wear </em></u><em>helmets when we bike together, as a rule.</em>)