阅读下列内容，从每小题所给的四个选项中选出一个最佳答案。
Biking is an amazing family activity, but finding a route that is suitable for different, ages is a little difficult. Lee McNeil and his family are crazy about biking. They have seven children, from 4 to 24 years old. When looking for a route, they look for enough protection from traffic, good surface condition and interesting views.
Here are some great routes for biking with your whole family which are suggested by McNeil.
Iron Horse Trail
This is the McNeil family's favorite ride. The route is 26 miles and goes through the 2.1 mile Snoqualmie Tunnel. "Beautiful views, the tunnel, and places to stop and watch the rock climbers make it special, " McNeilsaid." All ourkids have taken their turn to go through the black tunnel bravely for the first time and we celebrate it at the end of the ride." If you prefer, check http://bit, ly/Mlt9y4 for more information.
Centennial Trail
The Centennial Trail runs for 23 miles from Snohomish to Bryant. The trail iswide and smooth, and is safefor kids as it is off the roads. A nice stop is Lake Cassidy east of Marysville. A dock（码头） on the lakeis fun to explore. It also haspicnic tables and washrooms for a convenient（方便的） lunch-time stop. For a map, go to http：//bit. ly/L5qCeY.
Cascade Trail
The Cascade Trail is 23 miles. The slope（斜坡） is gentle and it makes for an easy family ride. McNeil said itis a "beautiful ride up the Skagit Valley, with lots of places to watch wildlife along the river". Go tohttp://bit, ly/PR4wOW tosee a map showing the trail, parking areas and bus stops.
Other good choices
Snoqualmie Valley Trail: http : // L. usa．Gov/n Wgwo
Guemes Island: http://bit, ly/LJ3RxL
Burke-Gilman Trail: http : //L. usa. gov/ s33li
