ie6,7折行问题

              <div class="left">
                    <div class="channel clearfix">
                        <span>品牌营销</span>
                        <div class="content">
                            <a>品牌曝光</a>
                            <a>品牌互动</a>
                            <a>品牌辨析</a>
                            <a>决策工具</a>
                        </div>
                    </div>
                    <div class="channel clearfix">
                        <span>效果营销</span>
                        <div class="content">
                            <a>知心推广</a>
                            <a>搜索推广</a>
                            <a>移动搜索推广</a>
                        </div>
                    </div>
                    <div class="channel clearfix">
                        <span>展示推广</span>
                        <div class="content">
                            <a>网盟推广</a>
                            <a>移动网盟</a>
                            <a>创意专家</a>
                        </div>
                    </div>
                    ...
                </div>
            
            
                <div class="right">
                    <div class="channel clearfix">
                        <span>品牌营销</span>
                        <div class="content">
                            <a>品牌曝光</a>
                            <a>品牌互动</a>
                            <a>品牌辨析</a>
                            <a>决策工具</a>
                        </div>
                    </div>
                    <div class="channel clearfix">
                        <span>效果营销</span>
                        <div class="content">
                            <a>知心推广</a>
                            <a>搜索推广</a>
                            <a>移动搜索推广</a>
                        </div>
                    </div>
                    <div class="channel clearfix">
                        <span>展示推广</span>
                        <div class="content">
                            <a>网盟推广</a>
                            <a>移动网盟</a>
                            <a>创意专家</a>
                        </div>
                    </div>
                    ...
                </div> 

.wrap .left {
    float: left;
    width: 360px;
    margin: 0 10px 30px 30px;
}
.wrap .right {
    float: right;
    margin: 0 30px 30px 0;
}
.wrap .channel {
    padding: 20px 10px 0 10px;
    font-size: 15px;
}
.channel span {
    float: left;
    width: 100px;
    vertical-align: top;
}

.channel a {
    white-space: nowrap;   //若没有此css，会出现奇怪的折行现象
    float: left;
    color: #999;
    text-decoration: none;
    font-size: 12px;
    margin: 3px 5px 3px;
}