单项选择题

This is an illness that can result in total blindness __________ left untreated.

A．after
B．if
C．since
D．unless

<上一题目录下一题>

热门试题

单项选择题

Acute hearing helps most animals sense the approach of thunderstorms long before people __________.

A．do
B．hear
C．do them
D．hearing it

单项选择题

Israeli Prime Minister Benjamin Netanyahu（）

A．has been prosecuted by the Justice Ministry.
B．may be prosecuted by the Justice Ministry.
C．has been prosecuted by the police.
D．will be prosecuted on Monday.