所以我尝试过的事情是：
1）
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 0C49F3730359A14518585931BC711F9BA15703C6
2）
echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/3.4 multiverse
3）
sudo apt-get update
4）
sudo apt-get install -y mongodb-org=3.4.10 mongodb-org-server=3.4.10 mongodb-org-shell=3.4.10 mongodb-org-mongos=3.4.10 mongodb-org-tools=3.4.10
但是我得到了这个错误：
E: Version '3.4.10' for 'mongodb-org' was not found
E: Version '3.4.10' for 'mongodb-org-server' was not found
E: Version '3.4.10' for 'mongodb-org-shell' was not found
E: Version '3.4.10' for 'mongodb-org-mongos' was not found
E: Version '3.4.10' for …