Follow the steps in each example to determine whether the sentence's structure is parallel or needs revision.

1. A well-designed Web page does not contain graphics that require excessive downloading time or using unusual, difficult-to-read fonts.

   Step 1. The items in the series are contain graphics that require excessive downloading time and using unusual, difficult-to-read fonts.
   Step 2. The items are both verb phrases; however, the verbs are not in the same form.
   Step 3. One of the items needs to be changed: for example, A well-designed Web page does not contain graphics that require excessive downloading time or use unusual, difficult-to-read fonts.

2. Fonts that are easy to read on Web sites include Verdana, Arial, and Helvetica.

   Step 1. The items in the series are Verdana, Arial, and Helvetica.
   Step 2. The items are all nouns. No change is needed.

3. It is usually easier for Web users to read text that is black type on a white or very pale background, at least 12 points in size, and try to use a non-ornate typeface.

   Step 1. The items in the series are black type on a white or very pale background, at least 12 points in size, and try to use a non-ornate typeface.
   Step 2. The items are not parallel. The first two items are phrases describing the text, while the third is an independent clause.
   Step 3. Change the third item to make it parallel with the first: It is usually easier for Web users to read text that is black type on a white or very pale background, at least 12 points in size, and written in a non-ornate typeface.

4. Many Web users still use only a 26K modem, a 15-inch screen, and a somewhat outdated browser.

   Step 1. The items in the series are a 26K modem, a 15-inch screen, and a somewhat outdated browser.
   Step 2. The items are all noun phrases. No change is needed.

5. Commercial sites that require users to wait for large graphics files to download are likely to frustrate users, lose sales, and customers may go to a competitor's site.

   Step 1. The series items are frustrate users, lose sales, and customers may go to a competitor's site.
   Step 2. The items in the series are not parallel because the first two are verb phrases, while the third is an independent clause.
   Step 3. The third item needs to be changed into a verb phrase: Commercial sites that require users to wait for large graphics files to download are likely to frustrate users, lose sales, and send customers to a competitor's site.