It is the first question parents ask when their child is diagnosed with autism(自闭症). Will his future brothers or sisters have a higher risk of (11) ________ it, too?
According to the largest study of siblings(兄弟姐妹) in families with autism, the answer is yes. Among 664 children who had at least one older sibling with the developmental disorder, the (12) ________ risk of autism was nearly 19%, (13) ________ higher than previous sibling-recurrence(复发) estimates that were anywhere from 3% to 10%. Kids with more than one older autistic sibling had an even higher risk of the disorder: 32%.
The (14) ________ suggest that genes play a key role in autism risk. But they also hint that other environmental factors (15) ________ by siblings, like influences in the womb(子宫)， may be important as well.
On the (16) ________ of the findings, the researchers recommend that doctors closely (17) ________ younger siblings of autistic children to pick up any early signs of the disorder, (18) ________ unusually large head or delayed language development and communication skills. Evidence suggests that early (19) ________ and diagnosis of autism can help children take advantage of therapies that can treat some of its (20) ________ .
A) average
B) basis
C) common
D) consequently
E) detection
F) developing
G) distributed
H) dramatically
I) including
J) monitor
K) reason
L) results
M) shared
N) symbols
O) symptoms
F
首先of为介词， 后面要跟动名词形式， 另外该句中的it指代autism（自闭症） ， develop的用法中有“患（病） ， 得病”之意， 符合句意， 故应填developing。
A
该句表示， “在至少有一个有发育障碍的哥哥姐姐的664名儿童中， 患自闭症的平均风险将近19”， 故选average， 表示“平均（数） 的； 通常的”。
H
分析句子成分可知， 该空应填副词， 则只有H项dramatically符合题意， 表示“显著地， 引人注目地”。
L
前面提到“根据……研究”， 并列举了一系列数字， 可知此处指代上文的“结果”。 The results suggest that ...意为“结果表明……”。
M
句意为： “其结果也暗示了其他由兄弟姐妹共享的环境因素”。 share表示“共享， 共用”。
B
on the basis of ...“根据， 按照； 在……的基础上”， 为固定用法。
J
句意是说“研究人员建议医生要密切关注患有自闭症孩子的弟弟妹妹们， 以及时发现该疾病的早期症状”。 monitor监视； 监测； 监督。
I
前面提到early signs of the disorder， 后面的large head or delayed language development and communication skills即对“早期症状”的举例说明， 故此处应填including。
E
后面是and diagnosis， 则此处应为与其对应的名词。 detection侦查， 探测； 发觉， 发现。 detection and diagnosis意为“（病例） 发现和诊断”
O
句意为“有证据表明， 对自闭症的早期检测和诊断有助于帮助孩子们利用疗法来应对其症状”。 symptoms表示“症状， 征兆”。