1,"r"前加"a"还是"an"?2,His father left here __ a month .(A.in B.later C.after D.from
问题描述：
1,"r"前加"a"还是"an"?2,His father left here __ a month .(A.in B.later C.after D.from
答
1."r"前用a 只有元音字母发音（a\e\i\o\u）开头的单词才用an
2.选C；A用于一般将来时的时间状语前
B用于时间后 e.g.a month later
Dfrom...to...