[syntaxnet]: why it cannot parse this simple sentence 'The answer is 4.'

[mw66]

@calberti or @andorardo.

I'm using the vanilla docker image:
https://github.com/tensorflow/models/blob/master/research/syntaxnet/g3doc/CLOUD.md

docker run --rm -ti -p 8888:8888 tensorflow/syntaxnet bash

I found it cannot parse some very simple sentences:

root@2d5f62fd6d59:/opt/tensorflow/syntaxnet# echo 'The answer is 4.' |  bash syntaxnet/demo.sh
...
INFO:tensorflow:Read 1 documents
Input: The answer is 4 .
Parse:
. . ROOT

and cannot parse similar simple sentence: 'You are a lady.'

root@2d5f62fd6d59:/opt/tensorflow/syntaxnet# echo 'You are a lady.' |  bash syntaxnet/demo.sh
...
INFO:tensorflow:Read 1 documents
Input: You are a lady .
Parse:
. . ROOT

[tensorflowbutler]

Thank you for your post. We noticed you have not filled out the following field in the issue template. Could you update them if they are relevant in your case, or leave them as N/A? Thanks.
What is the top-level directory of the model you are using
Have I written custom code
OS Platform and Distribution
TensorFlow installed from
TensorFlow version
Bazel version
CUDA/cuDNN version
GPU model and memory
Exact command to reproduce

[mw66]

Are you a robot?

I said clearly: vanilla docker image.

What is the top-level directory of the model you are using:
root@2d5f62fd6d59:/opt/tensorflow/syntaxnet

Have I written custom code
No

OS Platform and Distribution
vanilla docker image.

TensorFlow installed from
vanilla docker image.

TensorFlow version
vanilla docker image.

Bazel version
NA

CUDA/cuDNN version
NA

GPU model and memory
NA

Exact command to reproduce

root@2d5f62fd6d59:/opt/tensorflow/syntaxnet# echo 'The answer is 4.' | bash syntaxnet/demo.sh