` EX 3 `
` HTTTD `
` ( + ) ` : S + be + V-ing
` ( - ) ` : S + be not + V-ing
` ( ? ) ` : Be + S + V-ing
` DHNB `
` + ` ) Now
` + ` ) At the moment
` + ` ) ảt present
` + ` ) look !
` + ` ) listen !
` + ` )...
` 1 ` : is buying
` 2 ` : isn't studying
` 3 ` : is running
` 4 `: is eating
` 5 `: are you waiting for