Because it gives off rays which can be called signals. Hope this helps
The answer id D again. please mark my answer as brainliest.
Answer:
Has been traveling
Haven't heard
Hasn't sent
Have (you) heard
Has been putting
Have never tried
Have (you) been doing
Have been trying
Have (you) finished
Have (you) asked
Explanation:
The present perfect tense is the tense we use to talk about events that happened in the past but have present consequences. There are two types of this tense:
- The present perfect simple - used to talk about completed actions that have an influence on the present. The emphasis is on the result of the action.
- The present perfect continuous - used to talk about activities that started in the past and may continue in the present. The emphasis is on the activity itself.
You can see some more information about these tenses in the images I've attached below.