She let her head drop.

她把头垂了下来。

《柯林斯英汉双解大词典》

Try to toss the ball into the same spot every time? Let your racket head drop behind you and then hit the ball suddenly.

尽量在发球时每次都把球抛到相同的位置，然后将球拍举到头后方，瞬间击球。

youdao

The Head of the Russian Parliament's Foreign Affairs Committee, Konstantin Kosachev, has welcomed Washington's decision to drop plans for the missile defense system.

VOA: standard.2009.09.17

If we let our head drop, our heart drops with it.

CNN: Ironman champ: Train your brain, then your body

Drop my head a little bit, do the eyebrows.

CNN: From actor to auteur: Ben Affleck's career trajectory

"For him to go off nice and relaxed in 24 and change and come home on his own the way he did, and gallop out the way he did, and drop his head and walk home, it sent cold chills up my back, " the Hall of Fame trainer said.

WSJ: Derby winner Orb impresses with workout at Belmont