When a drum is hit with a stick, it creates a vibration, which makes a sound. The number of vibrations in a second determines what property of the sound? A. frequency

B. reflection

C. transmission

D .wavelength

acts of terrorism occur globally. the united nations global counter-terrorism strategy was created in order to build adequate systems of support and solidarity with victims of terrorism. here´s a summary of the proposed key themes: the importance of giving victims a face and a voice; protecting their dignity; giving victims legal status and defending their legal rights; providing victims with medical, psycho-social and financial support; building solidarity with victims; improving media coverage of victims; and focusing on the link between victims and counter-terrorism efforts more generally.

the period of human evolution has coincided with environmental change, including ('hominin' refers to any bipedal species closely related to humans – that is, on how do we know earth's climate has changed? a map showing dates and locations of prehistoric archeological sites and migration routes from africa into.