短语讲解：

1. The first of the two incidents took place April 11.

take place 发生，举行
例句：His graduation will never take place if he doesn't get to work.
如果他不下功夫，就永远不会毕业。

2. Two Russian attack aircraft flew past the USS Donald Cook 20 times, according to U.S. officials.

according to 根据，按照
例句：According to her, grandfather called at noon.
据她说,祖父在中午打来电话。