To support registering listeners from different threads, whatever mechanism is used to store and manage the list of active listeners must be thread-safe.

要支持从不同线程登记侦听器，那么不管用什么机制存储和管理活动侦听器列表，这个机制都必须是线程安全的。

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If you have dark skin or melasma, avoid these products, or choose 'active soy' products instead. Otherwise it's safe to use.

如果你皮肤暗沉或者有色斑，避免这些产品，或者选择“活性大豆”产品，除此之外，它是安全的。

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Active Protection is the best technology to keep you safe from emerging online threats.

主动保护是最好的技术，让您安全的新兴在线威胁。

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The revised adaptive cruise control system is now offered with Porsche Active Safe (PAS).

ENGADGET: Porsche Panamera S E-Hybrid plug-in model brings 416 guilt-free horsepower

One of the key goals of the trail upgrade is to create safe options for active transportation by improving lighting, traffic controls and other measures that have been shown to increase pedestrian safety and reduce injuries and deaths.

FORBES: Second in a series

The prudent use of coastal development setbacks or establishing a safe distance between buildings and the active beach zone can ensure that space is provided for a beach to move naturally, both during normal events and infrequent hurricanes, thereby ensuring the beach is conserved for all to enjoy and that coastal infrastructure remains intact.

UNESCO: Introduction