A piano doesn't like a drum. It doesn't sound like a drum, either(也). So how can the two be alike(相似的) ?

To play the drums, you use sticks. You hit the drums and the sound comes out. A piano is played in the same way. You hit the keys. The keys move hammers(锤) inside the piano. The hammers hit strings(琴弦) to make sounds. That's how a piano is like a drum.