2013年职称英语考试语法指导:地点状语从句2* O7 q( L a" M4 |7 r4 m
6、条件状语从句:if, unless, so (as) long as, in case, once, a far as, on condition that.
( H* i7 l3 u# s# r 注意if与unless的区别:不能用and连接两个unless从句,即不能有… unless …,and unless … 。但if … not and if … not却不受此限。 % E5 H/ Q$ {2 s7 H' m8 Y( I0 G: i. M
You won’t lose your weight unless you eat less and unless you exercise more.(×) , M$ C- d I% Y* G6 K
但可以说 … unless you eat less and exercise more. 8 F5 |; E% `) j
7、注意状语从句中从句的省略现象
" }- S: O% ^. R; H' W (1)连接词 + 过去分词
% z8 h1 U2 t x- G Don’t speak until spoken to.
1 d4 \4 T& f/ N6 F. L4 u" H) H+ n Pressure can be incrased when needed. 中华考试网
9 J( ^9 V6 P. O/ `+ ]" {9 A) S/ } Unless repaired, the washing machine is no use.
; y# O6 E$ k6 |, M (2)连词 + 现在分词 2 a9 {2 J Q M
Look out while crossing the street.
8 _" L/ C' n! i. }& E: K (3)连词 + 形容词/其他
) a5 E6 p$ L7 v* z1 g) B8 @; A0 ` 常见的有it necessary、if possible、when necessary、if any等。 |