晶状体半脱位（见图）常见于以下何种疾病（）

A．Marfan综合征

B．Marchesani综合征

C．同型半胱氨酸综合征

D．Sturge-Weber综合征

E．Axenfeld-Rieger综合征

翻译下列短语并完成句子。

1. a balanced diet ____

2. keep the balance of nature ____

3. keep one' s balance___

4. lose one's balance ( =be out of balance)___

5.  He ______ and hurt himself when he went upstairs.

6. It is difficult to for you to _____ onan icy pavement.