const time = () => {
body.style.background = 'red'
setInterval(() => {
body.style.background = 'gray'
}, 500)
}
bt2.onclick = function(){
bt2.style.display = 'none'
p3.style.display = 'none'
img3.style.display = 'block'
p4.style.display = 'block'
do{
setInterval(() => {
time()
}, 500)
}
}