involuntary 专八

1.He gave an involuntary smile.

他不由自主地笑。

2.Meg gave an involuntary exclamation.

梅格不由自主地叫起来。

3.When viewed from a microscope, there is no striation presented in the muscle, and moreover, since it is no controlled by our willpower, it is called involuntary, nonstriated muscle.

从纤维镜观察，平滑肌无横纹状结构，平滑肌不随人的意志收缩，故称不随意肌非横纹肌。