Mike _______(say) Chinese peopleare very friendly.

says/said

有这些可能：

says (that)

强调一直这么说

said (that)

强调曾经说过，可能现在不是

said 虽说是宾语从句，但中国人很友好可算是客观事实不跟主句时态变，而mike的话说过去了。就是过去时

says
由于Mike是第三人称单数，所以say+s
由于句子的复合宾语用的是现在时，所以主语的谓语应该用第三人称单数的现在时

Mike (said) Chinese people are very friendly.

says/said