Question

【题目】The girl was working hard. She hoped to finish cleaning the house _____ her mother came back home.

before

till

after

since

Answer 1

【答案】A

【解析】before在本句中作连词，引导时间状语从句。句意为：“那个女孩儿很努力地干着活。她希望再她妈妈回到家之前把房子打扫干净。”