heightened alert造句怎么写

Afghan intelligence appears to have been tipped off about the impending attack, and security forces were on heightened alert.

Elevated levels of both these chemical lead to heightened alertness and stimulate the forlorn animal to call for help and search for its abandoner-generally its mother.

Indian and Pakistani military forces are on heightened alert as a result of the growing tensions.

Germany was already on heightened alert.

Canadian airlines and airports went on heightened alert after authorities received credible intelligence of a potential terrorist threat, CTV News reported.