Polypropylene is known for its chemical resistance, making it a challenging material to bond with typical adhesives. However, specialized adhesives like Loctite Plastics Bonding System, which includes a primer to modify the surface for better adhesion, or 3M Scotch-Weld Structural Plastic Adhesive, particularly designed for difficult-to-bond plastics, provide reliable solutions. Surface preparation, such as cleaning and possibly corona or plasma treating, can significantly enhance bonding effectiveness. Additionally, polypropylene adhesive tapes, specifically formulated for polyolefinic surfaces, offer a no-cure-time alternative for lighter applications.

Yes, apples are a good source of dietary fiber. An average medium-sized apple contains about 4 grams of fiber, which is about 14% to 17% of the daily recommended intake. The fiber in apples is found in both the skin and the flesh, so consuming them unpeeled maximizes their fiber content. Fiber has several health benefits, including aiding digestion, contributing to feelings of fullness, and potentially helping to manage cholesterol levels. Apples contain both soluble and insoluble fiber, but it’s the insoluble fiber that primarily aids digestion and prevents constipation. The soluble fiber, on the other hand, is useful for controlling blood sugar levels and cholesterol. Including apples in your diet can be a tasty and effective way to increase your fiber intake and promote overall digestive health.

Downgrading Yarn, the popular package manager, can be necessary if a newer version is causing compatibility issues with your projects. Here’s how you can do it:

1. **Uninstall the current Yarn version:**
- If you’ve installed Yarn globally via npm, run `npm uninstall -g yarn` in your command line.
- For Yarn installed through other methods, refer to the specific uninstallation instructions.

2. **Install the desired version of Yarn:**
- Use npm by running `npm install -g yarn@version`, where `version` is the specific version number you want to downgrade to. For example, `npm install -g yarn@1.22.0` installs version 1.22.0.

3. **Verify the installation:**
- Confirm the downgrade by checking the version with `yarn --version`.

Remember, it's important to consider the implications of downgrading, as it may affect project dependencies or functionality. Always review the release notes for the versions you are switching between to ensure compatibility.