我躺在床上，听着墙上时钟的滴答声。

I lay in bed listening to the ___tick-tack of the wall clock.

孩子们在沙滩上用贝壳玩井字游戏。

The children were playing ___tick-tack with seashells on the beach.

孩子们用敲击桌面发出的滴答声来传递秘密信息。

The kids used ___tick-tack sounds on the table to send secret messages.