Which definition is the best for “semipermeable membrane”?

My question says on my assignment. read the following scenarios and decide which of the properties of life are being described. the first one is. katherine stopped on the way to school to grab some donuts. 2. because a dog cannot sweat, it has to pant in order to stay cool. 3. an elephant trun had no bone but 4,000 muscles. i have no idea what i am supposed to anwer. i can't find the answer in my notes or book that i can understand anyway

Which of these is most likely to happen if parallax measurements of star distances are taken after a gap of six months? the results would be accurate the results would be inconsistent the results would not be valid the results would not be repeated

What is the difference between how ionic and covalent bonds form