Okay, so I'm lazy. It's not interactive, but here's the answers.
| 40. Belly stalk (developing umbilical cord) |
| 41. Forebrain area |
| 42. Midbrain area |
| 43. Hindbrain area |
| 44. Eye |
| 45. Developing outer ear |
| 46. Heart prominence |
| 47. Liver prominence |
| 50. Notches between digital rays of hand |
| 51. Toe rays |