用适当的连词将两个句子合成一句,使句子通顺

题目

用适当的连词将两个句子合成一句,使句子通顺
1.Tom come back from school.his mother was doing some washing
2.Gina always sings .Gina is doing some cleaning

答案

1.Tom come back from school (while) his mother was doing some washing.
2..Gina always sings (while )she is doing some cleaning.