The colonization of land by plants appears to have begun about
A) 542 million years ago
B) 360 million years ago
C) 65 million years ago
D) 475 million years ago
D
You might also like to view...
Theoretical calculations indicate that a star more massive than some threshold around 15 or 20 solar masses will collapse and become a black hole when its nuclear fuel is exhausted
Indicate whether the statement is true or false
A transformer produces
A) energy. B) power. C) neither, but transforms mechanical energy to electric energy. D) none of the above
An image formed using a converging lens
a. is always real. b. is always virtual. c. can have negative magnification. d. can never be upright.
One kilogram of chilled water at 32°F (0°C) is placed in a freezer which is kept at 0°F (?18°C). Approximately how much electric energy (in kilocalories) is needed to operate the compressor to cool this water to 0°F if the room temperature is maintained at 75°F (24°C)? (Lice = 3.33 × 10^5 J/kg; cice = 2.09 × 10^3 J/kg/°C)
a. 13 b. 1.5 c. 15 d. 16 e. 33