练习: 1. Paragraphs 2 and 3 </p> 2. Paragraph 4 + f1 v* a% f k6 v3 s& B
3. Paragraph 5
3 A' v$ O- F- ]7 V 4. Paragraph 6 + T' x, l% S0 p; o
A Cloud-to-ground lightning occurring in the U.S.
) R2 N% L9 m" |: j, [& B B Types of lightning
1 T+ z+ m4 m( z/ J" A8 T1 [+ J2 M C Cause of lightning
# B; b0 `+ w! z D Differences between thunder and thunderstorm
7 C4 F+ V2 o3 v1 [4 W+ i# e E Frequencies of thunderstorms occurring in the world and the U.S. ) E5 c( J7 _1 Y# `" i: \
F Shock waves as thunder
8 h* j$ h3 G+ B 5. In most cases of cloud-to-ground lightning, the ground s surface … 4 L7 J3 H& S2 Z S4 m$ T
6. One form of lightning that … is ball lightning …
0 r( v8 [3 s2 s+ F3 M 7. Cloud lightning looks like a ribbon when its lighting channel …
9 S' ?/ t/ D. w% E 8. Although not fully understanding processes of lightning, man … # G) E$ o" C6 `4 g) v
A occurs most infrequently.
8 ~ y: x; M: o& x B is shifted sideways by strong winds. 中华考试网(www.Examw。com)
# C% r' V* X! q+ R C is often hidden from our view.
Z- G' d( v: b7 k D is equipped with a good knowledge of various forms of lightning .
6 x! J' a, d o# ] E is estimated at 20 millions a year.
1 P* Z$ K& C3 I ?( @, X9 l% o- _ F is positively charged.
. R/ k" \( g2 K, D4 n0 L4 J 参考答案:CBFE FABD |