In B, C and D, helps (singular) does not agree with differences (plural). Eliminate B, C and D, Hi, Mitch. In option B, the verb is not singular as you said "helps"(singular), but "help"(plural). Then, what is wrong with option B? Is it "in determining"? Thanks.

B/D - uses yields for plural trenches - wrong C - simultaneously not parallel to independently of - with is missing, having been is not necessary. A - that were - redundant or unnecessary and evidence for is wrong idiom. Between Past continuous and Simple past it is better to use simple tenses unle...

There is substantial evidence that certain forms of solar energy either now or within a few years will be economically competitive with conventional sources of heat and power. (A) either now or within a few years will be economically competitive with conventional sources of heat and power (B) will ...

A) Correct idiom would be: In contrast with the Yeti, B) Correct C) See A D) You are not comparing the dwelling E) See A Hi, I have a question. According to your reply, it seems that in contrast with and in contrast to are different. However, I don't understand the differences, they seem to be inte...