问题 单项选择题

燃烧带是炉缸煤气的发源地,若燃烧带减小则()

A、中心气流发展

B、边缘气流发展

C、中心过吹

D、边缘不足

答案

参考答案:B

多项选择题
阅读理解
阅读理解。
A. It can protect your brain from being hurt in a bike accident
B. Go for bike rides with your kids so you can show them what safe riding looks like
C. Never wear ear-phones while biking
D. You have to choose good shoes  
E. Check your child's bike to keep it safe and in good condition
     Bike Safety
     Bike riding is a great way to get exercise and fresh air and share time as a family. But before your kids
rush out and start biking, there's an important thing you need to consider -safety.
     Helmet (头盔)Basics
    Always wear a helmet when riding a bike, no matter where you are or how short the ride is. 1.  ___.
Here's why: Many bike accidents mean brain damage or death for someone who does not wear one
while riding. To protect against brain injury, make sure your kids wear a correctly fitting helmet on every
ride.
     Safe Clothing
     What kids wear when riding a bike is also very important for safety. Bright-colored clothes will help
kids be visible on the road. Besides, 2.  ____. Kids should never ride barefoot(赤脚)!
     Rules of the Road for Bike Riding
     Here are some must-know safety tips to teach kids:
     Stop at all stop signs and obey traffic lights just as cars do.
     Always stop and check for traffic in both directions when leaving a driveway. 
     3. ____. It's important to hear everyone else on the road.
     Making Safety a Family Activity
     One of the best ways to help kids learn safe bike riding is to set a good example by following the
rules of the road yourself. 4. ______. It's also a great way to stay active as a family and spend valuable
time with your kids!