But those tight bond angles of that triangular cyclopropane make it very fragile.

但是那个三角形环丙烷的紧密键角使它非常脆弱。

Instead, more practical concerns – like creating tighter bonds between families, or finding economic security – have historically been more common reasons.

相反，更实际的担忧——比如在家庭之间建立更紧密的联系，或寻求经济保障——历来是更常见的原因。

Pets who share their human's bed tend to have a " higher trust level and a tighter bond with the humans that are in their lives. It's a big display of trust on their part, " Varble said.

瓦布尔说，和人同床而眠的宠物通常“对主人更信任更亲密。这是宠物非常信任人类的表现。”