Please heat the meat thoroughly.
You guys should go through the proper channels.
Threading a needle is difficult.
This word consists of kanji with hiragana attached. Because the hiragana ends with an う sound, you know this word is a verb. You already learned that 通る means to pass, but this is a little different. You aren't the one passing, Sue (す) is. So you have to let Sue pass. That's why this means to let pass.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You learned this reading when you learned 通る. Switch the る for a す and you'll be all set!