at present是什么时态的标志

　　例：

　　1、Relations with neighbouring countries are under strain at present.

　　目前，与邻国的关系正处于紧张状态。

　　2、At present children under 14 are not permitted in bars.

　　目前，14岁以下儿童不允许进酒吧。

　　3、As things stand at present, he seems certain to win.

　　据目前情况看，他似乎胜券在握。

　　4、I'm sorry he's out at present.

　　很抱歉他这会儿不在。

　　5、There is no way at present of predicting which individuals will develop the disease