Why is halley's comet named after sir edmund halley? a. he was the first person to discover it. b. he calculated its orbit period correctly and estimated the time of its reappearance. c. he was dedicated to the field of astronomy. d. he was very famous at that time. e. he was the first to discover historical records of its observation.

What is true of all organisms in the kingdoms protista, plantae, fungi, and animalia? a. they are multi-celled. b. they are photosynthetic. c. they have cells that contain membrane-bound organelles. d. they contain cells that lack membrane-bound organelles.

The steps in the formation of extrusive igneous rocks are listed below in an incorrect order: 1. rock melts due to high temperature. 2. rock is buried deep under earth's surface. 3. magma is forced out of earth's surface during volcanic eruption. 4. lava cools and crystallizes to igneous rock. which of these best shows the correct order of steps in the formation of extrusive igneous rocks? 1, 3, 4, 2 2, 1, 3, 4 3, 4, 2, 1 4, 2, 1, 3

Adistinctive characteristic of mammals that is not observed in other vertebrates is