The <e1>polonium</e1> was contained in a <e2>tantalum capsule</e2> which was closed by beliarc welding remotely controlled manipulators.
The polonium was contained
The polonium was contained in a tantalum capsule which was closed by beliarc welding remotely controlled manipulators.
<triplet> polonium <subject> tantalum capsule <object> Content-Container(e1,e2)