In cockroach, identify the parts of the foregut in correct sequence:-
1. Mouth $\to$ Oesophagus $\to$ Pharynx $\to$ Crop $\to$ Gizzard
2. Mouth $\to$ Crop $\to$ Pharynx $\to$ Oesophagus $\to$ Gizzard
3. Mouth $\to$ Gizzard $\to$ Crop $\to$ Pharynx $\to$ Oesophagus
4. Mouth $\to$ Pharynx $\to$ Oesophagus $\to$ Crop $\to$ Gizzard

Which one of the following characteristics is incorrect with respect to cockroaches?