13 According to the passage, which of the following is NOT a possible way to detect mental retardation caused by diseases?
(A) Herpes simplex test
(B) Syphilis test
(C) Drug test
(D) Rubella test

There is no single cause of mental retardation遲緩；阻滯, but researchers have uncovered無遮蓋的 several causes, some of which are preventable可防止的，可預防.

Brain damage due to genetic conditions is a well-known cause of mental retardation遲緩；阻滯.

Most people are familiar熟悉 with Down’s syndrome唐氏綜合症, which is caused by the formation結構 of an additional chromosome染色體.

The normal number of chromosomes染色體 for people is 46; babies with Down’s syndrome have 47.

Another chromosome染色體-related cause of mental retardation遲緩；阻滯 is a malformation畸形（體） of the X-chromosome染色體.

Fortunately, blood tests can detect this problem early and immediate measures can be taken to limit the damage.

Not all brain damage resulting in導致；結果造成 mental retardation遲緩；阻滯 occurs because of problems in the genetic makeup of the infant.

Certain infectious（疾病）傳染性 diseases that the mother may contract患上，感染 during pregnancy can adversely不利的；負面的；有害的 affect the developing brain of the baby, particularly if the mother catches these diseases during the first three months of her pregnancy.

These diseases include rubella風疹, herpes simplex單純皰疹, and syphilis梅毒.

Because they are infectious（疾病）傳染性, to a certain extent面積，範圍；長度 they are preventable.

Another preventable cause of mental retardation遲緩；阻滯 in newborns relates to what the pregnant woman ingests攝取，嚥下（食物）.

Certain drugs are known to hinder阻礙，妨礙 the development of the baby’s brain such as thalidomide沙利度胺.

However, the most easily preventable cause of mental retardation遲緩；阻滯 is fetal alcohol syndrome胎兒酒精譜系障礙.

Drinking as little as one or two glasses of wine a week during pregnancy could result in physical and intellectual智力的，腦力 impairments損傷，損害, （身體功能的）障礙 in the infant.

According to the passage, which of the following is NOT a possible way to detect mental retardation遲緩；阻滯 caused by diseases? 

(A) Herpes simplex单纯疱疹病毒 test 

(B) Syphilis梅毒 test 

(C) Drug test 
(D) Rubella風疹 test