16 Nowadays many scientists depend on radiocarbon for dating age-old objects3 y5 M/ G$ w- b+ X' ^
A Right
+ H" y* k& l/ x$ O7 QB Wrong . I5 F* q L; C( V
C Not mentioned3 F" k( n9 P5 f* y% ]! @" P: e
17 The radiocarbon dating technique is only about 40 years old: b2 y# [* `1 H( S% l
A Right
+ j# a, C/ D/ a4 G# VB Wrong
2 g; S# t% i& |5 x! t tC Not mentioned
+ l: C' f" C) g# a! w18 An atom of ordinary carbon has six protons and eight neutrons
' r4 Z+ g8 n! I5 ]& l! K' fA Right
0 E* }) X* j+ M8 v) b% r# S- |B Wrong
9 c2 _( g; V& {- YC Not mentioned
7 }6 O* z9 X ^3 a9 x# t5 R9 `! }19 Radar is used to determine the characteristics of radiocarbon
2 V0 M7 j4 o- p* PA Right
+ ]- m ~5 _% Z, LB Wrong
% b2 _1 b: }% U9 @3 Z& tC Not mentioned
+ F4 `6 E* ^- R8 l4 Z, }20 Radiocarbon is reliable in dating an object back to at least 50,000 years; ~- ]# ~& d6 S3 p/ r+ Q
A Right $ r8 t# y6 y' T/ B" ~5 o
B Wrong 7 T: L2 N' i8 n1 s! m
C Not mentioned |
发表于 2012-8-16 00:07:50
