Step 1: Choose the combination of 4 doctors and 4 nurses with 4C2×7C4.

Step 2: Choose a doctor and two nurses to go to a place, which is 2C 1×4C2.

So a * * * has 4C2×7C4×2C 1×4C2.

It can also be solved by arrangement:

Two doctors were selected, and the first one was 4A2.

Similarly, four nurses are selected, and the first two nurses go to the first place, so there is 7A4, but at this time, the front and back positions are the same scheme, so the situation of nurses is 7A4/2A2/2A2.

A * * * has 4A2×7A4/4.