Static electricity: interesting experiments!

https://www.youtube.com/watch?v=ViZNgU-Yt-Y

https://www.youtube.com/watch?v=5TAIUCYMlIQ

Atoms

Passive voice and 1st conditional!

PASSIVE VOICE EXERCISES
https://www.ego4u.com/en/cram-up/grammar/passive/exercises?simple-present

https://www.ego4u.com/en/cram-up/grammar/passive/exercises

https://www.ego4u.com/en/cram-up/grammar/passive/exercises?simple-present-2

https://www.englisch-hilfen.de/en/exercises/active_passive/sentences_simple_present.htm

FIRST CONDITIONAL SENTENCES
https://www.englisch-hilfen.de/en/exercises/if_clauses/type_1_statements.htm

https://www.perfect-english-grammar.com/first-conditional-exercise-1.html

https://elt.oup.com/student/solutions/preint/grammar/grammar_07_022e?cc=global&selLanguage=en

https://www.ego4u.com/en/cram-up/grammar/conditional-sentences/type-1/exercises?02