He made another wonderful discovery, ______ of great importance to science.

A．which I think is

B．which I think it is

C．which I think

D．I think which is

被取保候审的犯罪嫌疑人、被告人应当遵守的规定有（）。

A、未经执行机关批准不得离开所居住的市、县

B、未经执行机关批准不得会见他人

C、不得以任何形式干扰证人作证

D、在传讯的时候及时到案