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A new effort is being launched to better educate parents about the earliest signs of autism (孤独症). Doctors at Maryland’s Kennedy Krieger Institute, one of the country’s leading autism centers, say they can now identify symptoms in children at a younger age than before. Children with autism withdraw into their own private worlds. Most children are not diagnosed until they are 3 to 5 years old, but the signs can appear as early as 6 months. “Most people use the rule of thumb that if a child is showing developmental delays before the age of 3, they’ll catch up, but children wi中国人自行设计和施工的第一条铁路干线是 A、京张铁路 B、京汉铁路 C、川汉铁路 D、津浦铁路