18. Lark Manufacturing Company initiated a voluntary Quality

Circles program for machine operators. Independent surveys of

employee attitudes indicated that the machine operators

participating in the program were less satisfied with their work

situations after two years of the program’s existence than they

were at the program’s start. Obviously, any workers who

participate in a Quality Circles program will, as a result, become

less satisfied with their jobs.

Each of the following, if true, would weaken the conclusion drawn

above EXCEPT:

(A) The second survey occurred during a period of recession when

rumors of cutbacks and layoffs at Lark Manufacturing were

plentiful.

(B) The surveys also showed that those Lark machine operators who

neither participated in Quality Circles nor knew anyone who did so

reported the same degree of lessened satisfaction with their work

situations as did the Lark machine operators who participated in

Quality Circles.

(C) While participating in Quality Circles at Lark Manufacturing,

machine operators exhibited two of the primary indicators of

improved job satisfaction: increased productivity and decreased

absenteeism.

(D) Several workers at Lark Manufacturing who had participated in

Quality Circles while employed at other companies reported that,

while participating in Quality Circles in their previous companies,

their work satisfaction had increased.（E）

(E) The machine operators who participated in Quality Circles

reported that, when the program started, they felt that

participation might improve their work situations.

不明白应该用什么思路？

这类except题很难，有什么好的解题方法？