0
votes
2answers
41 views

when relative clauses is needed

Some native speakers corrected sentence A to sentence B in my essay. Could anyone explain why here "brings to" is needed? A. The problem of foreign language class at primary school is the ...
1
vote
1answer
106 views

Restrictive relative clause or non-restrictive relative clause?

I am wondering whether to use a restrictive relative clause such as: "Multicopters belong to a family of aircraft called rotorcraft , which also includes helicopters, and although they appear to be ...
0
votes
2answers
289 views

“Non-restrictive appositive” vs. “non-defining relative clause”

Could you please kindly provide some explanation as to why the second option (B) is the only correct answer to the following question? And why is it not the case that both A and B could be correct ...
0
votes
3answers
2k views

Is it proper to use “that” instead of “at which” to refer to speed?

On a physics assignment, I believe that these sentences are grammatically incorrect, but some other students disagree (especially on the second one). What is the maximum speed that the mass can be ...