What unit is used to measure the distance between galaxies
a. light years
b. miles
c. kilometers
d. years

An alcohol thermometer makes use of alcohol's changing in order to measure temperature. as the temperature goes up, the alcohol contained in the thermometer increases in volume, filling more of the thermometer's tube.

Which position represents spring in the southern hemisphere? a) b) c) d)

The scheme below is from a series of reactions that are part of a synthesis of vitamin a. answer the following questions with reference to this scheme. (i) what is "reagent a"? (ii) draw a step-by-step mechanism which explains the formation of compound c from compound b (iii) which reagents would you use to form compound e from compounds c and d (reagents b and c)? for each reagent suggested above in (ii) explain the role of the reagent in the reaction to (iv) form compound e. you may wish to do this by drawing a mechanism. 1. addition of reagent a но reagent a 2. н,о" thо oh нон-с compound a. compound b. compound c .ch-оh 1. reagent b "сно 2. reagent c сh oh compound e. compound d.