When it rains, it does not always pour. During a typical storm, a (41. COMPARE) small amount of the lock-up moisture in each cloud reaches the ground as rain. So the idea that human intervention - a rain dance, perhaps - might encourage the sky to give up a little (42. ADD) water has been around since prehistoric times. More recently, would-be rain makers have used a more direct procedure - that of throwing (43. VARY) chemicals out of aero-planes in an effort to wring more rain from the clouds, a practice known as “cloud seeding”.

Yet such techniques, which were first developed in the 1940s, are (44. NOTORIETY) difficult to evaluate. It is hard to (45. CERTAIN) , for example, how much rain would have fallen anyway. So, despite much anecdotal evidence of the advantages of cloud seeding, which has led to its adoption in more than 40 countries around the world, as far as scientists are concerned, results are still (46. CONCLUSIVE) . That could be about to change. For the past three years (47. RESEARCH) have been carrying out the most extensive and (48. RIGOUR) evaluation to date of a revolutionary new technique that will substantially boost the volume of (49. RAIN) .

The preliminary (50. FIND) of their experiments indicate that solid evidence of the technique’s effectiveness is now within the scientists’ grasp.

Question

When it rains, it does not always pour. During a typical storm, a (41. COMPARE)                                                                small amount of the lock-up moisture in each cloud reaches the ground as rain. So the idea that human  intervention - a rain dance, perhaps  - might  encourage the sky to  give up a little (42. ADD)                                                                  water has been around since prehistoric times. More recently, would-be rain makers have used a more direct procedure - that of throwing (43. VARY)                    chemicals out of aero-planes in an effort to wring more rain from the clouds, a practice known as “cloud seeding”.

Yet such techniques, which were first developed in the 1940s, are (44. NOTORIETY)                 difficult to evaluate.  It is hard to (45. CERTAIN)       , for example, how much rain would have fallen anyway. So, despite much anecdotal evidence of the advantages of cloud seeding, which has led to its adoption in more than 40 countries around the world, as far as scientists are concerned, results are still (46. CONCLUSIVE)                                           . That could be about to change. For the past three years (47. RESEARCH)             have been carrying out the most extensive and (48. RIGOUR)                         evaluation to date of a revolutionary new technique that will substantially boost the volume of (49. RAIN)                                                                                 .

The preliminary (50. FIND)                of their experiments indicate that solid evidence of the technique’s effectiveness is now within the scientists’ grasp.

Timi · Accepted Answer

41. comparison
42. additional
43. various
44. notoriously
45. ascertain
46. inconclusive
47. researchers
48. rigorous
49. rainfall
50. findings

ngocanhnguyen · Answer

41. comparison
42. additional
43. various
44. notoriously
45. ascertain
46. inconclusive
47. researchers
48. rigorous
49. rainfall
50. findings

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