儿时，家住农村，每当春天到来时，为了吸引家燕住在自己家里，总要在屋檐下，房梁上搭一块小木板，为小燕子筑巢带来方便。
B-Time I-Time O B-Thing I-Thing B-Location I-Location O O O B-Time I-Time I-Time I-Time I-Time O O O O O B-Thing I-Thing O O B-Person I-Person B-Location O O O O O B-Thing I-Thing B-Location O B-Thing I-Thing B-Location O B-Metric I-Metric B-Thing I-Thing I-Thing O O B-Thing I-Thing I-Thing I-Thing I-Thing O O O O O