Copyright © ITmedia, Inc. All Rights Reserved.
Lifetime access to all 14 Babbel languages is just $159 (reg. $646.20) with StackSocial’s limited-time code LEARN.
，更多细节参见im钱包官方下载
This Tweet is currently unavailable. It might be loading or has been removed.
But e-bikes containing lithium-ion batteries are a newer challenge. "When a battery fails, it doesn't necessarily ignite, it will often produce some off-gases," says Stephen Welch, senior lecturer at the University of Edinburgh's Fire Research Centre. "Those off-gases are toxic and flammable. If they accumulate, you can have an explosion risk."