You have two options here. 

1- Use the Queue-Mode configuration option. The default, "host", creates one outgoing connection for each host. If you set it to "access" it will create one connection per URI type (which I understand to mean, one for http, one for ftp, and so on - since most connections are http, this means it'll access each server sequentially).

One way to do this that will also apply to update-manager is to:

echo 'Acquire::Queue-Mode "access";' &gt;/etc/apt/apt.conf.d/75download


if you want to try it with apt-get once to see if it helps:

apt-get -o Acquire::Queue-mode=access update


2- Use the Acquire::http::Dl-Limit option, this is similarly to reduce the bandwidth used to something your connection can handle (and as per the manpage, "this option implicit deactivates the download from multiple servers at the same time").

echo 'Acquire::http::Dl-Limit "70";' &gt;/etc/apt/apt.conf.d/75download


or

apt-get -o Acquire::http::Dl-Limit=70 update


Can the update manager download only a single package at a time?
After she killed the Levi squad, Eren transformed to fight the Female Titan. In Chapter 29, Hammer, it looked like Eren was having the upper hand, but then the Female Titan turned around, and with one horizontal motion, cut Eren's titan form's head in half.

How did that happen? That part wasn't clear in the anime nor the manga. Did she take a tree and smacked him? Did she harden her hand and hit him?


