Sentence Structure

Can you check these?

1- ...................................... , each of which may be used in a modern bridge according to the type of crossing required.

a- Some bridges are too low for river traffic to pass underneath

b- An arch bridge can cover a larger span than a beam bridge

c- The earliest bridges were tree trunks or stone slabs laid across a stream

d- Bridges have been used since ancient times to span deep rivers

e- There are a number of different kinds of bridge designs available

My answer is E

2- .................................................. , the country would need to admit more than 500,000 immigrants every year

a- Were Germany's population to remain at its present level

b- As long as the government keeps its promise to build a new hospital

c- Only if locals were unwilling to have some new immigrants

d- Even if the newcomers have no difficulty in adapting to their new lives

e- If the raise in population continues for a long time

My answer is A