Dependencies unknown

<properties>
    <boot-admin.version>2.3.0</boot-admin.version>
</properties>
<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>de.codecentric</groupId>
            <artifactId>spring-boot-admin-starter-client</artifactId>
            <version>${boot-admin.version}</version>
            <type>pom</type> <!--把依赖引入pom-->
            <scope>import</scope> <!--解决单继承问题，类似Parent标签-->
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
        <version>${boot-admin.version}</version>  <!--如果父pom中不设 type\scope 子pom中需要加上版本号-->
    </dependency>
    <dependency>
        <groupId>de.codecentric</groupId>
        <artifactId>spring-boot-admin-starter-client</artifactId>
    </dependency
</dependencies>