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题库 / Prep2007E2-SC-135
Whereas high speeds generally cannot be achieved by ramjets without their initially being assisted by a rocket, a scramjet, or supersonic combustion ramjet, can attain high speeds by reducing airflow compression at the entrance of the engine and letting air pass through at supersonic speeds.
Whereas high speeds generally cannot be achieved by ramjets without their initially being assisted by
Whereas a ramjet generally cannot achieve high speeds without the initial assistance of
With ramjets, high speeds generally are not able to be achieved without initially being assisted by
Unlike with ramjets, generally unable to achieve high speeds without the initial assistance of
Although a ramjet generally does not have the capability of achieving high speeds without the initial assistance from
capability to do;GMAT认为capability of X-ing/in X-ing是wordy/awkward的。
ability：sb&aposs ability to do sth或ability of sb/sth to do sth
capability to do不如ability to do简洁，但不可就此判错。
be able to do
be capable of doing
have ability to do ; ability of sb. to do
have capability to do doing ; capability of sb. to do doing
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