import xml.etree.ElementTree as ET

def replace_xml_tags(text):
    tree = ET.ElementTree(ET.fromstring(text))
    root = tree.getroot()

    # 遍历所有的标记并替换
    for elem in root.iter():
        if elem.tag == "tag1":
            elem.text = "replacement1"
        elif elem.tag == "tag2":
            elem.text = "replacement2"

    return ET.tostring(root, encoding="unicode")

# 测试文本
xml_text = '''
<root>
    <tag1>text1</tag1>
    <tag2>text2</tag2>
</root>
'''

replaced_text = replace_xml_tags(xml_text)
print(replaced_text)