3 · en
Short, simple sentences with “signals”, suitable for children and primary/elementary school, with common expressions and related words. You'll also find examples for middle and high school.
A helicopter spotted smoke signals from the castaway.
The inventor of the telegraph, Samuel Morse, invented a code based on these signals that could be translated into letters and, as a result, used to send messages.
If three or more stations detect that these signals exceed the background noise (technically called the "average normal level"), recorders with magnetic strips are automatically switched on, encompassing the set of transmitted measurements.
Free AI sentence generator: create age-appropriate sentence examples from any word. Ideal for students and language learners.