Question

2. I wonder why Joey hasn't written to us recently. We        by now. (hear)

我好奇为什么Joey最近没有写信给我们。现在我们该收到他的信了。

Answer 1

2. should have heard from him should + have done 表示"应该做到(但未做到) 某事"；hear from为固定搭配，意为"收到……的来信"。