题干
This memorial was built ______ those heroes who laid down their lives for the liberation of the black.
A：in memory of
B：in the honor of
C：in favor of
D：in search of
答案(点此获取答案解析）
A
”和“
”代表两种不同元素的原子。这两种元素分别组成的单质在点燃条件下发生反应，反应前后的微观模拟图如图所示，请回答下列问题：