单项选择题
A.<Select name="content"maxlength="3">……</select>B.<Select name="content"height="3">……</select>C.<Select name="content"size="3">……</select>D.<Select name="content"width="3">……</select>
A.内部联接 B.外键联接 C.外部联接 D.自联接
A.>= B.% C.or D.where