将下列数学术语翻译成英文（数字符号都须用英文） 2+8＝10 -7.5-(-6.8)＝0.7 │-5│＝5 √5＋√&#

two plus eight equals ten;
negative seven point five minus negative six point eight equals zero point seven;
the absolute value of negative five is five;
square root of five plus square root of five over eight;
two square equals four;
five cube equals a hundred and twenty-five;
three to the power of four equals eighty-one;
triangle ABC is similiar to triangle BCD;
triangle ABC is congruent with triangle DEF;
CD is the tangent line of Circle O;
positive and negative square root of sixteen equals positive and negative four;
x is bigger than five or x is less than or equal to negative four;
x is bigger than negative nine and equal or less than eight, x does not equal zero;
ABC is forty-five degrees;
AB and EF intersect at point O;
MN is perpendicular to AC;
DF is parallel with MN