HTML文档的树状结构中，（ ）标签为文档的根节点，位于结构中的最顶层。
A:
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A:
B:
C:
D:
举一反三
- 在HTML中，表示内嵌CSS样式的标记是（ ）。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/0f0459998c5c468d9f4da1cda1efa615.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/4defb3f96a4943559f8517f5fa1dd9b0.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/89f0de7112d641a1abb2c95a82733322.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/775faf4c538b484abd2b320e8d165e4a.png" />
- 在FeBr3存在下，下列化合物中与Br2最易反应的是 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/b390d91bdb2642eb922cda903d861e96.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/10344dabb53f493c909c2bcd1f2f7764.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/ec45a2a1fdd84ce0b3fd81823b9c375f.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/7c99b94959254b13b21e06a97f6ba58a.png">
- 肠道中的微生物与我们的健康息息相关，一般肠道中大约有多少微生物，可培养到的大约多少种？ A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/937c1a0cc6464dbcb8650e7289fd34de.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/eb2cc307fb9a4973a2175de99ab705e1.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/275f54ec97b0490f85a2955ab3c6fd89.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202009/b3a55c9c3ec94414b15f47d69823fe07.png">
- 如图所示电路的逻辑表达式F=（ ）。<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/8655693a417e4e43a32e0732ed533c96.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/beda73211aea49f082d9137fd4eb0526.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/7388c99ee0824f20bcf85893934a2f6a.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/9a5c81e78b344c79a9389e932a7f55ce.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/82193a9a030243728012b02e15718987.png" />
- 横桥的特性是（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/d9109b1706b24ebdaaa4fd2ade011f0b.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/3e73caf4907c4732b31655818429fd1f.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/22fe3c7df73445cdbc78681845eb442f.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/dda726f3f23e497ea5706434c05ee729.png"> E: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/1e933a32e7764e73841cf6d1ad056e95.png">