用be doing when do造5句

用be doing when do造5句,是陈述句, 用be doing when do造5句 用when be doing/do/does句型造十个句子 用be+doing +when be 可不可以用be doing,when be doing? 帮忙用was/were doing .when ; be about to do.when;had just done. 用 Sb who do sth be like sb else doing sth else who,when/once when do we have to be doing the research? 用 be doing 和be doing to do 造句 三个 be doing sth.when had juest done..when ,were/was doing..when,be about to do .. 请用be used to doing造1句