The mass of a star can be determined by studying
a. the wavelength of light emitted by the star.
b. the color of the star.
c. the distance between the star and earth.
d. binary star systems.

What did the first language sound like

Asap timed! 1. ice core samples from glaciers ice caps contain bubbles of ancient atmosphere that are in layers based on age. what questions are scientists most interested in? a. how the amount of water vapor needed to make the ice has changed b. how the amount of ozone has changed over time.c. how the amount of ice in each layer has changed over time d. how the amount of carbon dioxide has changed over time 2. what produces milankovich cycles ? a. sunspots ams solar flare on the suns surface b. changes in the earths orbit c. gravitational changes bases on the position of the sun and the moond. cycles of vegetation that result in desert and rainforest conditions

Which best describes how the common cold spreads in the human body? a bacteria burst out of normal cells killing them b viruses replicate inside respiratory cells c bacteria inject dna into normal cells d viruses insert dna into bacteria