---Are you sure you have to do it? It’s been very late.-----I don’t know ________I can do it if not now.A .where B. why C. when
__________ trees are yellow in autumn.
-- Who are you going with? -- ____________________
______ are you doing this evening?
-- Will you be back _____ five in the afternoon? -- I am not sure, maybe later than that.
Who is _________ in your school, Mr Wang or Ms Lee?