同义句转换Class4 held an evening party on the playground last weekend ——on the

同义句转换Class4 held an evening party on the playground last weekend ——on the
1、·Class4 held an evening party on the playground last weekend.
·_____on the playground____class 4 held an evening party last weekend.
2、·I didn't understand what she meant until she explained it to me again.
·Only after she explained it to me again_____what she meant.